Didn’t work for me unfortunately. I tried compressed air on all the idler pulleys (I found 10), did a spray of IPA, adjusted belt tension.
not sure if belt rubbing is the issue, or if there are other pulleys.
Is it ok to grease the top/bottom edges of the belt?
update:
it seems it is ok to apply grease Horrible Squeaking, possibly ball screw bearing - #7 by soulrider911 but i don’t fancy doing it, it will end up full of dust and bits of filament.