Is it mostly the drivers window sticking?
Check to see that the rear edge guide isn't broken loose.
That's on the outer edge of the door down low. The original one screws in
with a single screw. The new Volvo part goes in with a pop rivet.

There's something else, maybe you should do windows one at a time
since the motors draw high current, if you do two at a time there's more voltage drop and less efficient motors. Just a hunch, let me know if you see a difference.

Maybe there's a lube for the edge guide, spray silicone?

Wouldn't hurt to service the battery cable ends.

Bill