Same thing here.

When I initially spawn them everything is ok and they patrol correctly.
After I go to another part of the map however and i come back (and the garrison spawns back in)
they just stand there in formation without patrolling.

Not gamebreaking but it does break the immersion a bit.

Trying different things to solve it and if I do I will post it here.
If anyone has a solution in the meantime it would be appreciated.