If the fan is out of balance it will run rough and be much louder. The front of the blades on the exhaust fan need to be cleaned periodically, because build up on the edges will cause it to run out of balance.
I just cleaned mine manually a couple of days ago…it’s running much quieter. But on the Pro models, that can take a couple of hours. (I still prefer to do it that way, to make sure I get everything.)
There is a way to clean the fan using a special non-flammable degreasing spray and Glowforge has a special routine that you can run while using the spray.
Both the links to the routine and the manual cleaning instructions are here: