Replying to FKS forward pressure screws backing out

I have a question for any FKS gurus out there.

I have a pair of FKS 120 bindings, and the forward pressure never seems to stay the same. I will tighten up the forward pressure, and then 1-2 ski days later I will have developed toe slop in at least one binding. Currently, I'm just tightening them as needed, but I feel like this is less than ideal. Any one have this problem before or know how to fix it?

Also, my pair seem to different length arms? In order to get the same amount of forward pressure. If you are familar with FKS, you will know that there are three reference bands on the bindings to help with adjusting forward pressure. I need to have one set a full band further back than the other binding just to have them set at the same forward pressure (double checking with a measuring tape.)The bars also are always hitting my boots, which is kind of annoying as its digging holes into the plastic of my boots.

All this makes less than confident in the bindings. Today I took some slams where I felt like they should've come out but didn't.... any advice?