Static?

We're having tremendous problem trying to get sheets to feed into our folder. Humidity had got really low due to 2 weeks of single digit temps here, but it's coming up some now inside, with our humidifiers and some make shift measures running full time.

Its a Stahl folder with the feed table, not a stream fed folder. The sheets are aqueous gloss coated 2 sides but had no spray powder applied, even on the 2nd side, and have sat for at least 4-5 weeks in the pressroom\bindery uncovered. 2-3 weeks after side 1 and then 2-3 weeks more after side 2 printed.

Do you think this is just static? Would applying the spray powder on side 2 helped it? Should we have wrapped the skids off the press between passes? Some, or all, of the above?
We did get pressman to apply spray powder on the last 2 runs but they haven't hit the folder yet to see if that helped any.

If you try to pull a sheet straight off the pile, there is a lot of tension, it is amazingly hard to get it to slide, lot of surface tension if that's the right term.

Any insight appreciated.