Hello and welcome – This forum isn’t super active, so you might also want to check out our closed Facebook group. (Visit Facebook, search for @GDATF, click “join group”, and then answer the new member questions when your notifications light up.)
It’s possible for hyperthyroidism to recur post-RAI if there was tissue left behind, but it’s also not uncommon to need a dose tweak over time (for example, if you experienced a significant amount of weight loss.) Hopefully, the endo will be able to shed some additional light.