I am having the same possible issue. If bearing problem, how to replace the bearing?
It is a very easy fix if you have changed out brushless motor bearings before. If you haven't then it is still fairly 'easy' but you just need to be methodical and careful.
Basically, there are two bearings on the Inspire motors, one upper, one lower on the motor shaft situated in the bell housing for the upper and the motor housing for the lower.
Remove the offending motor to get access to the bottom. CAREFULLY remove the e-clip on the bottom making sure it doesn't ping off into hyperspace never to be found again !!!!!!
Then remove the thrust washer.
The motor will now come apart although it maybe a little difficult to separate since the magnets are strong.
Once you have the motor in two you will need to remove the upper and lower bearings. That can be easy in some cases or very difficult in others, depending on tolerance and how tight they are.
DJI use a poor quality bearing in their motors (they always have in my opinion) so get yourself some decent replacements.
They are standard sized 6852Z Metal Shielded bearings available pretty much anywhere on the planet! They can also be known as 685ZZ or 6852ZR
Standard dia: 5/11/5 (Bore 5mm, OD 11mm Width 5mm).
Reverse the whole procedure and enjoy flying again.
Br advised that it is best practice NOT TO REUSE an e-clip more than once. Many do but it is advisable to replace with a new clip each time since they do not fair well to repeated removal and replacement stress.