Big shot pro help please

[Anirtak191]

Hi all. I have a big shot pro and have had it for a couple of years now. Recently I have started noticing the cutting isn’t as good. Part of the dies are not cutting out. Sometimes changing the paper/cardstock I am using seems to make a difference. Sometimes adding an extra shim helps but not all the time. And it is not the areas closer to the middle that aren’t cutting properly.
And it always seems to be the same part of the die that is not cutting properly no matter what way I put it onto the cutting plate and roll it through.
Does any one have any ideas at all why this could be happening all of a sudden.
Many thanks
Kat