Wylie, thanks for posting your settings! Until now, I never really bothered looking at the settings for bambu basic petg to spot the difference to other petg settings, because I don’t have their petg. Now I did, and it’s obvious: The cooling fan starts at 10% when layers last 30s or longer and runs fastest with 40% when layers are only 8 seconds to complete:
I printed LOTS of petg with a fan starting at 40% and maxxing at 90%, with the same layer times of 30 and 8s. Try your print again with these setting, I bet you will succeed.
Don’t know why bambu sets values so low for their own petg - looks rather like ASA settings to me.
I will start a new topic about it the next days.