Just chiming in here, I also have this on a X-T5 and a 23mm XF 1.4 R (not the newer model), every 20-30 focus's the motor will just continue to make a noise until you either AEL or AF again (these are both brand new, so was checking to see who else had the issue, relieved its just not just me!)
Here is a video of the "issue", so is this normal?
Note, this does not occur with the 16mm XF WR 2.8.