Metronome stops working, anyone else experienced this?

This problem has been around for years - since C6 IIRC. I found a workaround, but it relies on your audio interface’s mixer…

Create a Cue output, set it to receive click and nothing else. Now use your audio interface’s mixer to route this output to where you need it. You should find this works solidly.

I do this with an RME Fireface 800 and just send the click cue to a spare DAW output there. Works 100% for me that way.