First you are shooting into a multi layered foam target and then assessing your arrow flight. No two arrows will be sitting the same, I also have a multi layer target, and have for years.

First, increase your point weight to 150 - 170 grains, I shoot the same arrow, same length but use a Longbow.

How are your arrow flying to the target, are they flying straight or is the tail off to one side, I suspect the later due to point weight.
have you shot your current set up with a broadhead on there? that will tell you real fast if you are underor overspined.