I would say the wet film sits for a minute or two. I usually reverse roll the film, then roll it from top to bottom of the glass. First squeegee pass light to medium pressure, starting at top middle and working down and to the sides, so the bottom part of the window has been sitting for a minute or two before being squeegeed. Then I trim edges, and squeegee again same direction but with more pressure watching to make sure the water gets pushed out.
Regardless, I've been using the same process and water/slip for years with no issue, then suddenly this