MCP server connects and quickly disconnects. Further connections are not established.

The MCP server initially allows a client to connect, but the connection quickly terminates. Then, when the client tries to connect again, it fails because the server fails to properly respond due to the error 'Session not found for sessionId'.

```
2025-09-01 08:17:07,661 [ 92795] INFO - #c.i.m.l.c.q.QuotaManager2Impl - From external: null, 3016341.5985, 25000000, 2026-06-06T21:00:00Z
2025-09-01 08:17:07,661 [ 92795] INFO - #c.i.m.l.m.j.b.a.JunieGrazieLLMProxy - Quota is updated
2025-09-01 08:17:07,661 [ 92795] INFO - #c.i.m.l.a.m.AiaActivationTransmitter - Received message from junie: activation_complete
2025-09-01 08:19:18,949 [ 224083] INFO - io.modelcontextprotocol.kotlin.sdk.server.KtorServer - New SSE connection established and stored with sessionId: 8ee061c5-1eb3-48f5-b10a-16ddcc4c367d
2025-09-01 08:19:18,949 [ 224083] INFO - io.modelcontextprotocol.kotlin.sdk.server.KtorServer - New SSE connection established and stored with sessionId: 139e64c9-d285-4cd9-8e89-ee81b44d0ee5
2025-09-01 08:19:19,092 [ 224226] INFO - io.modelcontextprotocol.kotlin.sdk.server.Server - Handling initialize request from client Implementation(name=claude-ai, version=0.1.0)
2025-09-01 08:19:19,092 [ 224226] INFO - io.modelcontextprotocol.kotlin.sdk.server.Server - Handling initialize request from client Implementation(name=claude-ai, version=0.1.0)
2025-09-01 08:19:19,094 [ 224228] WARN - io.modelcontextprotocol.kotlin.sdk.server.Server - Client requested unsupported protocol version 2025-06-18, falling back to 2024-11-05
2025-09-01 08:19:19,094 [ 224228] WARN - io.modelcontextprotocol.kotlin.sdk.server.Server - Client requested unsupported protocol version 2025-06-18, falling back to 2024-11-05
2025-09-01 08:20:18,014 [ 283148] INFO - io.modelcontextprotocol.kotlin.sdk.server.Server - Server connection closing
2025-09-01 08:20:18,014 [ 283148] INFO - io.modelcontextprotocol.kotlin.sdk.server.KtorServer - Server connection closed for sessionId: 139e64c9-d285-4cd9-8e89-ee81b44d0ee5
2025-09-01 08:21:23,128 [ 348262] WARN - io.modelcontextprotocol.kotlin.sdk.server.KtorServer - Session not found for sessionId: 139e64c9-d285-4cd9-8e89-ee81b44d0ee5
2025-09-01 08:21:25,166 [ 350300] INFO - #c.i.p.i.s.IjentSessionMediator - IjentId(ijent-0-wsl-Ubuntu) log: ijent_service::processes::definition: Attempt to close already closed stdin
2025-09-01 08:21:25,367 [ 350501] INFO - #c.i.j.n.n.WorkingDirectoryDependentNpmPackageVersionManager - Version fetched successfully: 10.9.2; command: "C:\Program Files\nodejs\npm.cmd" --version, duration: 537ms
2025-09-01 08:25:24,010 [ 589144] WARN - io.modelcontextprotocol.kotlin.sdk.server.KtorServer - Session not found for sessionId: 139e64c9-d285-4cd9-8e89-ee81b44d0ee5
2025-09-01 08:25:26,134 [ 591268] WARN - io.modelcontextprotocol.kotlin.sdk.server.KtorServer - Session not found for sessionId: 139e64c9-d285-4cd9-8e89-ee81b44d0ee5
```

The client is configured this way:

```
"jetbrains": {
"command": "C:\\Program Files\\JetBrains\\IntelliJ IDEA 2025.1.3\\jbr\\bin\\java",
"args": [
"-classpath",
"C:\\Program Files\\JetBrains\\IntelliJ IDEA 2025.1.3\\plugins\\mcpserver\\lib\\mcpserver-frontend.jar;C:\\Program Files\\JetBrains\\IntelliJ IDEA 2025.1.3\\lib\\util-8.jar",
"com.intellij.mcpserver.stdio.McpStdioRunnerKt"
],
"env": {
"IJ_MCP_SERVER_PORT": "64444"
}
},
```

The client registers the same problem:

```
2025-09-01T13:21:23.121Z [jetbrains] [info] Message from client: {"method":"tools/call","params":{"name":"list_directory_tree","arguments":{"directoryPath":".","maxDepth":1}},"jsonrpc":"2.0","id":4} { metadata: undefined }
Error in Socket: java.lang.IllegalStateException: Error POSTing to endpoint (HTTP 404 Not Found): Session not found
Error in StdIO: java.lang.IllegalStateException: Error POSTing to endpoint (HTTP 404 Not Found): Session not found
```