Commenting because I feel like I’ve been gaslit by people saying that I should have no problems because they can print Bambu PETG basic just fine. I’m sure some batches of PETG are fine, but I have had the same experience as you with their PETG.
I’ve tried multiple different spools in different colors and cannot get it to print well, even after drying and calibrating just like you.
I’ve tried the fixes outlined in this post and by a redditor here but to no avail.
For reference I’ve been 3D printing since ~2016 and haven’t had this many problems with any other plastic or brand of filament before. It’s frustrating, since the X1C is what I use for work and I hate that I’m stuck with a bunch of filament that I can’t figure out how to print.