I want to make sure you are checking the correct fan…the one we are talking about is hidden underneath the laser arm…directly behind the carriage plate that the head sits on. You can’t see it unless you turn off the machine and pull the laser arm to around the middle of the bed - then if you lean over behind the arm you will see that fan.
If it gets really junked up, it might be slowing it down and it might need cleaning. The process for doing that is a bit involved since you have to remove the carriage plate. Instructions for how to do that are here:
You might want to take a look at that and see if it needs cleaning.