Boarding patrol vessels is impossible now. If you try to walk around inside of one you get stuck on invisible walls everywhere you try to move. It doesn't matter if the ship isn't moving at all.
Do you have a save game where you are next to such a vessel that this happens with when you load in ? Can you attach it here please ?
I left my character at the vessel in this save. This one is planetary. If you want to test it from scratch, just disable any vessel's movement in any way (power, thrusters etc) and try entering the ship and moving around.
Fix is on the latest exp build B2206 https://empyriononline.com/threads/alpha-experimental-9-3.47312/ Please test if you have the time.