Gaggia Classic Pro Can't Tighten Portafilter Problem

If anyone knows the permanent fix for this I would be extremely grateful. I have had my Gaggia Classic Pro for about 3 months. I haven't been using super fine grinds. I use 18 grams of grounds per shot. Lately after making 3-4 shots of espresso I can't tighten the portafilter basket at all. I can barely get it inside the group head before it can't move anymore without applying a TON of force.
As you can see in the video simply removing the shower screen and the shower screen holder and putting it back on without doing any cleaning solves the problem, but WHY?? It doesn't seem like it is a problem with there being a lot of coffee build up inside of there otherwise I would have the same problem after putting the shower screen holder back on.
I ordered a new 8mm gasket from #WholeLatteLove and I'm awaiting its arrival. I really don't want to have to take off the shower screen holder every 4 shots of espresso.