I haven’t visited this site for several years. Hello again and I hope I may be welcomed back in

I have a Meridian Sooloos system with a MD600 and a MS600. Probably a bit ‘old hat’ by now but it has been working reasonably reliably until now.
I cannot get my MS600 to function.
1) It doesn’t appear in Meridian Sooloos Configuration
2) In Control:PC I can view my files
3) In the top right corner of Control:PC I can only see ‘Control:PC on DESKTOP-U9CVIEB’ but not ‘MS600’
4) On my iPad I get a drop-down box at top right saying ‘Zones – please select a zone’. This doesn’t work which ties in with 3) above
5) Checking in my router manager I can see that the MS600 is connected but no data has been sent or received
6) I’ve changed the Ethernet cable. The indicator lights at each end are showing correctly
7) When I turn on the MD600 (using the rear switch) the light on the on/off button on the front illuminates initially blue and then eventually to white. When I turn on the MS600 (using the rear switch) the light on the on/off button on the front illuminates initially white and then eventually to blue. I believe that blue is the standby indication? I’ve tried pressing the front button on the MS600 to turn it from blue to white after the initial startup.
8) I’ve gone through the routine several times of turning everything off (PC, router, ethernet switch, MD600, MS600) and then restarting in varying sequences. In the past when there have been any problems I’ve found that doing this routine sorted things out.
I’m starting to wonder if there is a fault in the MS600. I don’t know if Meridian will still do repairs on a MS600 but before I pack it up and send it off I want to sure I haven’t missed anything obvious.
Any comment will be much appreciated. Thank you