schema manager update tool available command no longer works

Describe the bug
The schema-manager tool fails with the available command.

We run our FHIR Server using the OSS container in Azure App Service and use the schema manager dotnet tool to upgrade the schema when necessary. I just updated the schema tool to the latest version (it had been a long time since doing this) and now I get a variety of errors when running the available command.
For example, schema-manager available -s https://ourfhirserverurl returns an error
Unhandled exception. System.ArgumentNullException: The SQL connection string cannot be null or white space.

If however I add the the --connection-string parameter I then get errors
Unrecognized command or argument '--connection-string'
Unrecognized command or argument (myconnection string)

FHIR Version?
R4

Data provider?
SQL Server

To Reproduce
Steps to reproduce the behavior:
See above

Expected behavior
Show the available schemas for the fhir server

Actual behavior
A range of error messages requiring connection strings but not allowing them to be set

Start with the schema-manager available command and reproduce it against the R4 FHIR Server using SQL Server, first without and then with the reported --connection-string argument. Trace how the command obtains its SQL connection string and parses arguments. Done means available shows the server's available schemas without the null-connection error or rejecting the connection-string option.