Question Changed TA part. after OTA

Hi guys!

I got a C1904 earlier this month and one of the first things I did is root it and backup the TA partition. I dont remember the exact software version though I think it might have been some 15.1.A.XX. So after a 90MB OTA update to latest 15.1.C.2.8, I take a TA backup again. This time I get a different TA..img (different checksums). I wanted to know if this is normal. Also note that I didn't do anything root/bootloader related on the phone (except maybe install Titanium Backup and get rid of some bloat).

Learned advice is greatly appreciated.