Mind controlled enemy doesn't rejoin combat, just stands there till combat finishes

Difficulty “Hard”
On “Spear of Heaven” took out all single enemies that I could no issues, regular game play.

Took out “Cardinal Hanson - lvl35” from high up in the church a few local enemies came to help, mind controlled one of them, but not the Level 35 MIMIR Z600 (thank god) combat ended.

I then killed the “MIMR Z600” (EMP shocked it with a weapon mod then took it down), once I’d killed it combat mode continued (strange).

I realised there was still a “Sect Tank” which hadn’t been activated (just stood there) as it was really far away so I killed that, combat continued.

So I roamed the map in combat mode till I found a “MIMR floaty bot thing (couldn’t remember the name)” at the other end of the map…after it died combat continued!

There is nothing else alive on the map but I can’t leave combat mode.

Update: loaded an earlier save just after killing the Cardinal noticed that the guy I mind controlled was still in the church even though I’d emptied the chest after killing everyone (I thought) so I killed him and then took out the MIMIR Z600 without any issues. Everything working as normal now.

Issue was after being mid controlled units don’t join the action and just stand there until combat ends, if you’re no where near the unit by that time you assumed you’ve killed them all.
Just happened again.