I am trying to debug a Go program in VS Code, using WSL. The program compiles and runs, but when trying to debug with dlv dap, it seems to hang and never reach the first breakpoint. I am using go 1.17, dlv 1.7.2 and Ubuntu 20.04. The problem is replicated with the simple Hello World program:

package main

import "fmt"

func main() {
    fmt.Println("hello world")
}

If I chose Run->Run Without Debugging, the Debug Consol shows
Starting: /mnt/f/mattm/home/go/bin/dlv-dap dap --check-go-version=false --only-same-user=false --listen=127.0.0.1:53252 --log=true --log-output=rpc --log-dest=3 from /mnt/f/mattm/home/hw
DAP server listening at: 127.0.0.1:53252
hello world
Process 17851 has exited with status 0 dlv dap (17754) exited with code: 0
The program has run and exited successfully (though why start dlv if not debugging?) But if I try to Run->Start Debugging, the console window only shows:
Starting: /mnt/f/mattm/home/go/bin/dlv-dap dap --check-go-version=false --only-same-user=false --listen=127.0.0.1:56084 --log=true --log-output=rpc --log-dest=3 from /mnt/f/mattm/home/hw
DAP server listening at: 127.0.0.1:56084
The program does not appear to execute, VS Code never shows execution reaching a breakpoint. (The outcome is the same whether or not I've set breakpoints). Task Manager does show a dlv-dap process running; it appears to be hung and waiting for something. But what? If I terminate debugging under VS Code, the dlv-dap process remains. It is as though VS Code spun off the dlv process and then forgotten about it. Do I need to prompt VS Code to connect to the DAP server to proceed? How do I do that?

Addendum: I am using the following launch configuration:

"name": "Launch Package",
"type": "go",
"request": "launch",
"mode": "debug",
"program": "${fileDirname}",
"logOutput": "dap,debugger",
"showLog": true,
"dlvFlags" : ["--only-same-user=false"]

After turning on verbose dlv logging (as in the config above), I get the following:
Starting: /mnt/f/mattm/home/go/bin/dlv-dap dap --check-go-version=false --only-same-user=false --listen=127.0.0.1:51444 --log=true --log-output=dap,debugger --log-dest=3 from /mnt/f/mattm/home/breezepms/hello-world DAP server listening at: 127.0.0.1:51444 2021-10-17T16:35:27+01:00 debug layer=dap DAP server pid = 7019 2021-10-17T16:35:27+01:00 debug layer=dap DAP connection started 2021-10-17T16:35:27+01:00 debug layer=dap [<- from client]{"seq":1,"type":"request","command":"initialize","arguments":{"clientID":"vscode","clientName":"Visual Studio Code","adapterID":"go","locale":"en-gb","linesStartAt1":true,"columnsStartAt1":true,"pathFormat":"path","supportsVariableType":true,"supportsVariablePaging":true,"supportsRunInTerminalRequest":true,"supportsMemoryReferences":true,"supportsProgressReporting":true,"supportsInvalidatedEvent":true}} 2021-10-17T16:35:27+01:00 debug layer=dap [-> to client]{"seq":0,"type":"response","request_seq":1,"success":true,"command":"initialize","body":{"supportsConfigurationDoneRequest":true,"supportsFunctionBreakpoints":true,"supportsConditionalBreakpoints":true,"supportsEvaluateForHovers":true,"supportsSetVariable":true,"supportsExceptionInfoRequest":true,"supportTerminateDebuggee":true,"supportsDelayedStackTraceLoading":true,"supportsLogPoints":true,"supportsClipboardContext":true,"supportsSteppingGranularity":true}} 2021-10-17T16:35:27+01:00 debug layer=dap [<- from client]{"seq":2,"type":"request","command":"launch","arguments":{"name":"Launch file","type":"go","request":"launch","mode":"debug","program":"./hello-world.go","logOutput":"dap,debugger","showLog":true,"dlvFlags":["--only-same-user=false"],"__configurationTarget":5,"packagePathToGoModPathMap":{"/mnt/f/mattm/home/breezepms/web/xmlutilities":"/mnt/f/mattm/home/breezepms/web/xmlutilities","/mnt/f/mattm/home/breezepms/ledgers":"/mnt/f/mattm/home/breezepms/ledgers","/mnt/f/mattm/home/breezepms/web":"/mnt/f/mattm/home/breezepms","/mnt/f/mattm/home/breezepms/web/filehandling":"/mnt/f/mattm/home/breezepms/web/filehandling","/mnt/f/mattm/home/breezepms/persistence":"/mnt/f/mattm/home/breezepms/persistence","/mnt/f/mattm/home/breezepms/cmd/csvloader":"/mnt/f/mattm/home/breezepms","/mnt/f/mattm/home/breezepms/hello-world":"/mnt/f/mattm/home/breezepms"},"debugAdapter":"dlv-dap","apiVersion":2,"dlvLoadConfig":{"followPointers":true,"maxVariableRecurse":1,"maxStringLen":64,"maxArrayValues":64,"maxStructFields":-1},"showGlobalVariables":false,"substitutePath":[],"dlvToolPath":"/mnt/f/mattm/home/go/bin/dlv-dap","env":{},"__buildDir":"/mnt/f/mattm/home/breezepms/hello-world","__sessionId":"8e201eb7-88ec-452f-896d-3d5e98596c05"}} 2021-10-17T16:35:27+01:00 debug layer=dap debug backend is 'default' 2021-10-17T16:35:27+01:00 debug layer=dap building program './hello-world.go' in '/mnt/f/mattm/home/breezepms/hello-world' with flags '' 2021-10-17T16:35:29+01:00 debug layer=dap running binary '/tmp/__debug_bin3449446367' in '.' 2021-10-17T16:35:29+01:00 info layer=debugger launching process with args: [/tmp/__debug_bin3449446367]