iPhone SE 2nd Generation Storage Bug

My iPhone SE 2nd generation 64GB started having issues with storage after around 6 months of owning it. The first issue I had was the storage would say that about 40GB of storage was taken up by apps, and I deleted as many apps as I could and the storage did not change. I brought it to Apple and they factory reset the phone which fixed the issue, they just said it was a strange bug. The issue started again not long after but it was slightly different, it now says that just over half of the total 64GB is taken up by iOS and when I check how much it’s actually taking up at the bottom, it says 8GB. I deleted an app that was using quite a bit of storage and it went from 46GB used to 44GB, but within a few seconds the iOS filled that back up to 46GB used. I don’t want to keep resetting the phone because I lose all my data in apps and the problem will most likely just come back not long after, I’m not sure what to do but I’ve had the phone for over a year now and upgraded to a 12, I would still like to be able to use the SE though and get the issue resolved.