In -1/Access on the seed "FlyingDamperNanovents", there's a Swarmer squad near the top-right Garrison.
That Swarmer squad kept changing the target of their patrol, without the squad leader actually ever moving more than three tiles from their starting point.
Eventually, the squad actually managed to reach one of the targets.
Example (right at the end of the gif) :
I had visited a Garrison that led me to Access and got the patrol data from a terminal there, which is how i could see the patrol paths.
I know that patrols can normally decide to change up their target early, but usually they still manage to move at least more than a few tiles towards it.
I guess my report might be more about that swarmer squad having great difficulty moving along their patrol path for some reason?
(Side note : Which is better, gifs (which can be embedded here) or videos (which have more time control)?)