After I fitted new 3D printed end caps to my M2000, the networking section of the unit has failed with the 'No net connection!' error for both Ethernet and WiFi. Obviously I disturbed something.
Having stripped it and found nothing visibly wrong, my next port of call - in the absence of anyone in UK doing repairs any more - would be trying different network boards. From this article I believe the older M1000s with connections under the end caps had the same stacked pair of network boards inside. If anyone - ideally UK - has one with functioning networking to sell, please let me know.