AC fan issues

[mrt6644]

When Im running my AC sometimes, I notice that the fan speed speeds up and decreases on its own.
Does anyone have the same thing?
Is this controlled by the electronics? or do I have a faulty switch or fan?
I have the manual temp controls (non-Premium).

 

[TRUSTYAXE]

Cabin filter clean?

 

[mrt6644]

Yes, I change it twice a year.
I also notice a small noise from fan. Wonder if debris got into the fan blades.
Sometimes it seems that it regains speed after hitting a bump, making me think its an electrical connection or switch issue.
Of course the dealer couldn't reproduce it

 

[flyrv9]

I haven't looked, but perhaps the owners manual has info on fan speed.