Please pass this onto the software development team.
I get the “air assist fan error” frequently, but never when the fan does actually need cleaning.
It triggers nearly always after I have taken the print head off for cleaning and put it back again. So the trigger is not being caused by the fan speed at all.
The fan can be as clean as a whistle and the error message will still appear.
I have found cleaning the contacts - the gold strip connectors on the carriage and the pins on the printer head will help. Nine times out of ten rubbing a wet finger on the gold connectors is what it actually takes to make it work.
Once I have it working, it will usually run happily all day long until I take the print head off for cleaning again.
I suspect you are using resistance to check for fan speed. I don’t know if it is my UK weather, the humidity rating of my shed or something else entirely.
I have a basic and a pro - I see the exact same problem on both machines.
This morning I have spent 3 hours trying to get past this error.