I have a SWG and keep my FC at 7 to 8 at all times and my CYA is at 80... With your CYA at 60 it can be harder on your SWG/FC and the FC can dip lower.. I would bring your CYA to 80 and keep FC at 7 to 8 and you should be great...
I had the same exact thing happen 2 times with my pool, both...