I was printing PLA, it looks ok up to a certain height (although it was warping slightly), but then it becomes ugly.
I will do a test print of the same height, butaybe you already have an idea.
Maybe something got stuck in the nozzle, partly clogging it. Try cleaning it. A trick I often use is to start the nozzle preheating and then yank the filament out of it as soon as it becomes warm enough for that to be possible, that usually pulls whatever crud was stuck in the nozzle out along with it.