It only grows well in the pot. Mine looks the same as yours. Some hostas are like that.

I would venture to say "seasonal uglies". but saying that, I would be sure to clean up any and all dead and dying leaves and then in the Spring, just as the pips are emerging but before they leaf out I would douse the clump with hydrogen peroxide.

Bacterial streak. Remove all leaves after first frost. Do not compost. Just part of opportunistic uglies.