The size of your river bet sucks.

Any two pair hand like a 9x is going to call, but probably would have called quite a bit more and feels he just got let off easy.

Any Tx (nonboat) hand is probably going to raise allin, but is never folding to any bet of yours anyway, so you migh make it a bit more.

Any full house is gonna push on your ass, and you're not deep enough to considering folding, so it's not like you lose less to better hands by leading 1/5 pot.

Finally, the flop did not have a ton going for it draw wise, so it's unlikely that villain has a busted hand that he decided to bluff with over your janky bet.

Basically I think you need to bet more. What works pretty well with this hand is if you pot the flop and pot the turn, you can push all in on the river with being too much of an overbet. Although actually, given that his most likely hand is a T, as played you might as well just overbet push river anyway since it's not like he is folding.