This side effect is not uncommon post-RAI and going down the road, even a few months later.
I had 200 mci RAI, lost my sense of taste TOTALLY for 2 months.
Got that back slowly over a few weeks.
Now I struggle with the tightness of the jaw, salivary gland pain, the spurts of the sour blocked up saliva,... small price to pay, and be still walking this earth!
My endo suggests also sucking on sour candies to help the glands unblock...the advice we follow post RAI is what we should be following now with the salivary problem.
Good Luck!