How do you know if you’re in a “flare up?”

6 months ago I was diagnosed. My TPO was at 267. 3 months later, TPO was 338. This last week my TPO was 167. TSH, T3 and T4 have been in range the whole time. Not taking any thyroid meds. Does this mean when I was diagnosed I was having a flare up? I have done minimal lifestyle changes- cut gluten in half and lost 35lbs with semaglutide but that’s it.