I haven't hosted the missions. I can't justify sharing them if I'm forcing people to take on Taliban, OPF_F and IND_F all at the same time.
The problem is just so strange. I can teleport around the map and see nothing but the correct faction for ages, until eventually a vanilla squad will appear.
Like I said I thought I had this fixed by deleting and replacing all of the OPFOR entities and modules and not using any feature (such as the new Intel option) that was causing errors. In some cases this has given me success but in other cases it simply does not work.
I have to wonder at this point if this is happening to other people too, but that they'd just not know about it. To see this happen one would need to teleport to all units on the map and wait for them all to spawn in around them. In some cases I need to go around the map twice, teleporting to every virtual unit generated by ALiVE.
If you were actually "playing" the mission and not testing, in some cases someone could probably play for hours and hours and not actually see this happen. Other times you'll see it pretty much right away.