Tiger Salamander not eating

I have had my barred tiger salamander for about three years now and he has always been a very good eater. Recently, however, he just doesn’t seem very interested in food and has gone about 9 days now without eating. He is a good weight (not at all underweight) and I know he has enough fat storage to go a little bit without eating but I am getting increasingly concerned.
His temp is about 65 degrees or so and he is currently not on substrate but instead on paper towels (he is prone to skin infections and due to several instances of open sores, I have had to have him on paper towels for about ten months now in order to keep everything clean. It really works wonders). I do my best not to keep him too wet, but the paper towels are never totally dry. I have not changed anything recently that might stress him and stop him from eating.
I’ve never been able to get him to eat a pinky, but he is usually very quick to snatch up different types of worms and crickets.

Is it possibly he is feeling the barometric pressure change with fall coming in? I really cannot think of any other reason why a usually voracious eater would suddenly completely stop. If you guys can think of anything, please let me know! I’m very worried about my little boy!! 