I re-updated firmware, and although you can stop and start it as normal through the app centre again it now constantly gets stopped by the NAS after a minute or so with the following message:
Error 2020-11-02 14:11:56 System 127.0.0.1 App Center App Installation [App Center] Channels DVR has an invalid digital signature. The app has stopped and cannot be installed on QTS. You can remove it in the App Center.
So am reverting my firmware yet again ...
