Unable to launch debugger in Visual Studio 2022: "launch: program '' does not exist."

Environment

Host: Windows 11, Visual Studio 2022 17.5.1
Target: Debian Buster armv7l
Target dotnet: v6.0 installed at ~/dotnet. vsdbg installed at ~/vsdbg

Bug Summary

When launching vsdbg via plink with DebugAdapterHost I get "launch: program '' does not exist."
Previously the dotnet app runs fine on the target, and I can also Attach to Process using ssh and debug the application.
I run launch.json by calling "DebugAdapterHost.Launch /LaunchJson:"launch.json" /EngineGuid:541B8A8A-6081-4506-9F0A-1CE771DEBC04". I have turned DebugAdapterHost logging on, and dump output is below.
From the log output the plink connection appears to connect, and vsdbg starts, but then fails with the "launch: program '' does not exist." message.

launch.json

{
  "version": "0.2.0",
  "adapter": "C:\\Program Files\\PuTTY\\plink.exe",
  "adapterArgs": "-i ssh-key.ppk debian@10.1.1.206 -batch -T ~/vsdbg/vsdbg --interpreter=vscode",
  "configurations": [
    {
      "name": "Remote @ 10.1.1.206",
      "type": "coreclr",
      "cwd": "/home/debian/SCIProg",
      "args": [],
      "program": "/home/debian/SCIProg/SCIProg.dll",
      "request": "launch"      
    }
  ]
}

Dump output

 1> DebugAdapterHost version: 17.4.60824.2 commit:8f4cb8b63aaa8b4b64f8bc0920832bedc7dd4832
 1> State: Unset => Initializing
 1> Sending VS event: IDebugEngineCreateEvent2 (fe5b734c-759d-4e59-ab04-f103343bdd06)
 1> Sending VS event: IDebugProgramCreateEvent2 (96cd11ee-ecd4-4e89-957e-b5d496fc4139)
 1> Starting 'C:\Program Files\PuTTY\plink.exe' with arguments '-i ssh-key.ppk debian@10.1.1.206 -batch -T ~/vsdbg/vsdbg --interpreter=vscode'
 1> [DebugAdapter] --> C (initialize-1): {"type":"request","command":"initialize","arguments":{"pathFormat":"path","clientID":"visualstudio","clientName":"Visual Studio","adapterID":"coreclr","locale":"en-US","linesStartAt1":true,"columnsStartAt1":true,"supportsVariableType":true,"supportsRunInTerminalRequest":true,"supportsMemoryReferences":true,"supportsProgressReporting":true,"SupportsMessageBox":true,"supportsHandshakeRequest":true,"supportsVsAdditionalBreakpointBinds":true,"supportsHitCountsChange":true,"supportsVsCustomMessages":true,"supportsVariableEnumerators":true},"seq":1}
 1> WARNING: Request 'initialize-1' has not received a response within 1000 ms!
 1> [DebugAdapter] <--   R (initialize-1) [1738 ms]: {"type":"response","request_seq":1,"success":true,"command":"initialize","body":{"supportsConfigurationDoneRequest":true,"supportsFunctionBreakpoints":true,"supportsConditionalBreakpoints":true,"supportsHitConditionalBreakpoints":true,"supportsEvaluateForHovers":true,"exceptionBreakpointFilters":[{"filter":"all","label":"All Exceptions","description":"Break when an exception is thrown. ","default":false,"supportsCondition":true},{"filter":"user-unhandled","label":"User-Unhandled Exceptions","description":"Break when an exception is caught in non-user code (system code) after having passed through user code. ","default":true,"supportsCondition":true}],"supportsSetVariable":true,"supportsGotoTargetsRequest":true,"supportsModulesRequest":true,"additionalModuleColumns":[{"attributeName":"vsLoadAddress","label":"Load Address","type":"string"},{"attributeName":"vsPreferredLoadAddress","label":"Preferred Load Address","type":"string"},{"attributeName":"vsModuleSize","label":"Module Size","type":"number"},{"attributeName":"vsLoadOrder","label":"Order","type":"number"},{"attributeName":"vsTimestampUTC","label":"Timestamp","type":"unixTimestampUTC"},{"attributeName":"vsIs64Bit","label":"64-bit","type":"boolean"},{"attributeName":"vsAppDomain","label":"AppDomain","type":"string"},{"attributeName":"vsAppDomainId","label":"AppDomainId","type":"number"}],"supportedChecksumAlgorithms":["MD5","SHA1","SHA256"],"supportsExceptionOptions":true,"supportsValueFormattingOptions":true,"supportsExceptionInfoRequest":true,"supportTerminateDebuggee":true,"supportsSetExpression":true,"supportsReadMemoryRequest":true,"supportsCancelRequest":true,"supportsExceptionFilterOptions":true,"supportsExceptionConditions":true,"supportsLoadSymbolsRequest":true,"supportsModuleSymbolSearchLog":true,"supportsDebuggerProperties":true,"supportsSetSymbolOptions":true,"supportsHitBreakpointIds":true,"supportsVsIndividualBreakpointOperations":true,"supportsVsBreakpointLanguage":true,"supportsSetHitCount":true,"supportsVsCustomMessages":true,"supportsEvaluationOptions":true,"supportsExceptionStackTrace":true,"memoryReferencesAreAddresses":true,"supportsObjectFavorites":true,"supportsObjectId":true,"supportsVariableEnumerators":true},"seq":1}
 1> Sending VS event: IDebugEngineMetricsUpdatedEvent166 (45b79d58-0620-410f-8f39-c7c8c155e36c)
 1> [DebugAdapter] --> C (launch-2): {"type":"request","command":"launch","arguments":{"name":".NET Core Launch 10.1.1.206","type":"coreclr","cwd":"~/SCIProg","args":[],"program":"SCIProg.dll","request":"launch"},"seq":2}
 1> [DebugAdapter] <--   C (handshake-2): {"type":"request","command":"handshake","arguments":{"value":"zJoylcOcMStAhoPaiG+G7oOEIMsHiX30zhcffPeG8/4="},"seq":2}
 1> [DebugAdapter] --> R (handshake-2): {"type":"response","request_seq":2,"success":true,"command":"handshake","body":{"signature":"243mvbEPjpHYJ7KsGwevbmZ6gPEI9tGp81gdOi51oKHkpI="},"seq":3}
 1> [DebugAdapter] <--   E (output): {"type":"event","event":"output","body":{"category":"console","output":"-------------------------------------------------------------------\nYou may only use the Microsoft .NET Core Debugger (vsdbg) with\nVisual Studio Code, Visual Studio or Visual Studio for Mac software\nto help you develop and test your applications.\n-------------------------------------------------------------------\n","severity":"ok"},"seq":3}
 1> Sending VS event: IDebugMessageEvent2 (3bdb28cf-dbd2-4d24-af03-01072b67eb9e)
 1> [DebugAdapter] <--   E (output): {"type":"event","event":"output","body":{"category":"telemetry","output":"VS/Diagnostics/Debugger/vsdbg/LaunchFailed","data":{"VS.Diagnostics.Debugger.vsdbg.Distribution.Version":"10","VS.Diagnostics.Debugger.vsdbg.Distribution.Name":"debian","VS.Diagnostics.Debugger.vsdbg.ErrorCode":1002,"VS.Diagnostics.Debugger.vsdbg.Version":"17.6.10208.1 commit:e3225483cd173944b74f30a50c6625a0ce60dfa5","VS.Diagnostics.Debugger.vsdbg.AdapterId":"coreclr","VS.Diagnostics.Debugger.vsdbg.OSFamily":"Linux"}},"seq":4}
 1> [DebugAdapter] <--   R (launch-2) [39 ms]: {"type":"response","request_seq":2,"success":false,"command":"launch","message":"launch: program '' does not exist.","seq":5}
 1> ERROR: Unexpected error

AggregateException: One or more errors occurred.

Aggregate exception: 
    DebugAdapterLaunchException: Failed to launch debug adapter.  Additional information may be available in the output window.

    Failure Location: LaunchRequest
    Inner Exception: 
        ProtocolException: launch: program '' does not exist.
Inner Exception: 
    DebugAdapterLaunchException: Failed to launch debug adapter.  Additional information may be available in the output window.

Microsoft.VisualStudio.Debugger.VSCodeDebuggerHost.Engine.Implementation.DebuggedProcess.<StartDebugAdapter>b__115_3(Exception ex)
Microsoft.VisualStudio.Debugger.VSCodeDebuggerHost.Utilities.TaskExtensions.<>c__DisplayClass11_0`1.<Catch>b__0(TException ex)
Microsoft.VisualStudio.Debugger.VSCodeDebuggerHost.Utilities.TaskExtensions.<>c__DisplayClass10_0`1.<Catch>b__0(AggregateException ex)

    Failure Location: LaunchRequest
    Inner Exception: 
        ProtocolException: launch: program '' does not exist.

 1> ERROR: One or more errors occurred.

Failed to launch debug adapter.  Additional information may be available in the output window.

launch: program '' does not exist.
 1> Sending VS event: IDebugErrorEvent2 (fdb7a36c-8c53-41da-a337-8bd86b14d5cb)
 1> State: Initializing => Exiting
 1> State: Exiting => Exited
 1> Sending VS event: IDebugProgramDestroyEvent2 (e147e9e3-6440-4073-a7b7-a65592c714b5)
 1> [DebugAdapter] <--   E (initialized): {"type":"event","event":"initialized","body":{},"seq":6}
 1> WARNING: Ignoring event of type 'initialized' received after moving to 'Exited' state!
 1> Debug adapter process exited.

Start with the reported launch.json and the DebugAdapterHost.Launch entry point, then compare the configuration in the file with the launch request shown in the dump output. Check how the remote vsdbg session handles cwd and program before returning "launch: program '' does not exist." Done means the same launch configuration starts SCIProg.dll successfully through plink.