I’ve had a similar problem, but only with WIFI-only connections.
I started a support ticket, but Formlabs tech support was asking me to do things that were not convenient (connecting direct to the router would require a ridiculously long cable, and I already know I don’t have any problems that way, etc).
Power cycling recovers the connection. But better than that, keeping the printer ON, while cycling the Wifi off/on seems to be just as effective.
The printer still drops the wifi connection once and a while, but the above work-around works. If you depend on being away from your printer for long periods of time, this won’t really help, though.