Yes that 15 amp breaker was popped, I'm sure at its peak it's pulling over 15amps. I agree the wire gauge is all the same size.
Honestly was kinda happy when i found this. It has never tripped b4 but I had a lot running making sure everything was working for the season.
So should I move it back or just but a 20 amp breaker in the slot? Either way is fine and would be nice to have the 3rd ac separated from everything.