Game not stopping (steam) after close

Issue description

After quit from COI menu the game reports "stopping" but never completes the exit process.
Furthermore, cannot launch a new instance of COI - reason "the game is already running".
However, the "launched" or running does not show in windows task manager.

Reproduction steps

1. Save the game
2. Quit
3. Steam Hub says stopping but does not stop.

Game version and build number

latest - can't access the game to check

Operating system

Windows

Attachments

Uncertain which "file" should be attached to provide information required. COI or Steam?

Really, no idea what the issue is. If the game is not in Windows Task Manager, it sounds like some Steam issue. We don't control this flow.