RemoteServiceException only when starting service from callback

Question

My app is starting a foreground service when the user tap on a button. The service starts if and only if the user grants all the permissions (3), here is the code of the fragment:

private val permReqLauncher =
            registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { permissions ->
                val granted = permissions.entries.all {
                    it.value
                }
                if (granted) {
                    mService.startAnswering()
                } else {
                    if (shouldProvideRationale()) {
                        Snackbar.make(...

Here is the listener on the button:

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        binding.fab.setOnClickListener {
            if (!MotoAnswer.isServiceRunning) {
                if (hasPermissions())
                    mService.startAnswering()
                else
                    permReqLauncher.launch(PERMISSIONS)
            } else {
                mService.stopAnswering()
            }
            updateUI()
        }
    }

The problem is that, if the service is started from the registerForActivityResult, then I get the exception, otherwise all is fine. This means that if it's the first time the user tries to start the service, he get the exception; starting from the second time all is fine.

Here is the stack:

Fatal Exception: android.app.RemoteServiceException Context.startForegroundService() did not then call Service.startForeground(): ServiceRecord{c7a5885 u0 org.punkeroso.motoanswer/.AnswerService} android.app.ActivityThread$H.handleMessage (ActivityThread.java:2047) android.os.Handler.dispatchMessage (Handler.java:106)

com.android.internal.os.ZygoteInit.main (ZygoteInit.java:967)

Do you have any clue on why this is happening? It seems fine to me but, obviously, this is not.