When using a campaign on Dnd Beyon'ds MAPS for in person play, I have an HDMI out to a second screen which a digital table top we use for the minis. However the Maps tool will randomly just stop working, and I'll have to refresh it on the DM side, reload it, then stop the game, pull up the map then drag it back over to the digital table top again, which is pretty frustrating as it happens often. Has anyone else have this issue?

Everyone does because it's a deliberate in-built feature for resource management control. You're using the maps tool in a way it was not intended. You're meant to be using it frequently - as in players using the maps to move their tokens and you moving monster tokens and scenes and fog of war - so to save resources it will time out the session if nothing happens for an extended period of time. This is deliberate intended behaviour, not a bug.