I've run into a similar issue, where I ended up falling indefinitely during a siege, as well as just getting stuck in general a few times. The current spot I'm in doesn't have me perpetually falling, but stuck between rocks that I fell in between. It is not limited to any specific map.
There really needs to be some kind of "stuck button" or something that can move you, assuming there are no enemies within range, to a spot nearby or to a static location on any map.