I noticed that there is an “Test:PM-Fail” issue with the new Pixhawk firmware V3.2.1.  

This message shows up there:

Test: Autotune = UNKNOWN - No ATUN log data

Test: Balance/Twist = GOOD -

Test: Brownout = GOOD -

Test: Compass = GOOD - mag_field interference within limits (13.38%)

Test: Dupe Log Data = GOOD -

Test: Empty = GOOD -

Test: Event/Failsafe = GOOD -

Test: GPS = GOOD -

Test: IMU Mismatch = GOOD - (Mismatch: 0.53, WARN: 0.75, FAIL: 1.50)

Test: Parameters = GOOD -

Test: PM = FAIL - 63 slow loop lines found, max 10.33% on line 72730

Test: Pitch/Roll = GOOD -

Test: Thrust = GOOD -

Test: VCC = GOOD -

 With firmware V3.2, the same drone, I didn't have this issue.  After I upgraded it to V3.2.1, the fail message showed up.

Any help about why this might happen would be appreciated.