So depending on your RDOs you should have at least two days at your new CPC pay. I would definitely get with your secretary and sup to see when your paperwork was filed etc. But there is a chance it will be amended on your next pay stub. I’d probably wait for that before blowing it up.
I wouldn’t sweat the 1.6% much. I was worried about it one of my previous moves and after doing the match it didn’t really change much either way. Especially when you break it down by pay period. Unless you were a developmental instead of CPC-IT and the 1.6% disappears at the bottom of the band. Then that sucks.