Mine has been very stable, however it did disconnect several days ago but restarting fixed it, no doubt you have tried that. Does it happen during play or after being in standby mode for awhile ?
Welcome to the forum and sorry you’re having this problem. It could be the Bridge or it could be network related. Strange things can happen with networks. For example, I once had a switch go bad. As suggested rebooting everything is a good idea. Turn off everything then reboot, starting with your router and any switches, then your PC or Mac (or NAS or whatever), then the DS last. Try different ethernet cables if you can (they can definitely go bad–one time a cable that shorted took out every device on my network (temporarily) and it was a real pain to isolate it). Also, does the Bridge show up on Fing? Can you ping the Bridge using Fing? Fing is a free app available for iDevices and Android that can tell you a lot about your network devices.
I am having Roon disconnects, although the Roon logs suggest a RAAT issue as I am seeing server buffer overruns.
I do see 3.5.1 of the Bridge is out and I just upgraded from 3.5.0. Not sure if this will help… but hoping no more disconnects. It seems random and can run for hours without issue then it would drop off.