EDIT: Now including all bug report information
I'm having a similar issue but with SPARKs. For some reason the SPARK in this mission can't get off this building at all. Every other soldier and the VIP were fine to jump down the drainpipes but the SPARK can't go anywhere, although I did manage to get him down to this balcony and back up again.
Tried every edge of the roof and it doesn't show any valid route down:
Not sure if it is something to do with the 1.1 update and not starting a new game?
Version: 1.1
OS: Windows 10
Other mods: None
Circumstances: Began a VIP extraction mission with a SPARK, spawned on a high rooftop. Started campaign with 1.0 so got SPARK early
Savegame: Yes