I started raising my Alk slowly 1 year ago. I run all 9 tanks with the same salt.
This might be your issue. While there are definitely acro tanks which seem to do well at higher Alk, I find the majority to do well at closer to natural seawater. When I dropped mine years ago was when my acros really started doing well. IMO RSCP salt is designed for people who don't dose which is why the levels are so high. I run mine +/- 7.5.