Yeah, well I've leraned to expect unusual results, as I've observed several anomolies that have not shown up on lab systems, so I always have a rollback plan.
Currently running
iMC PLAT 7.1 (E0303P13) Max. License Quantity: 250 used 200
iMC NTA 7.1 (E0301P05) Max. NTA Devices: 5 used 4
iMC UAM 7.1 (E0302P16) Max. License Quantity:800 used 171 (this is low because the backup/failover systems has most of them until they all reauth)
iMC WSM 7.1 (E0303P08) Max. APs: 250 used 13 (uplift from PCM gave me all these and UAM)
Not such a custom or elaborate install I would think. All installed on one server so maybe something I did early on with UAM install/config has come back to bite due to a change they made.
The diversity of the potential conbinations makes it impossible to comreprehensively test, and as you have mentioned with your lab, the actual environment data and operations seems to produce differences.
And not even consistently - i recently posted about a problem running cli - they were erroring can't telnet to device. Even though the telnet config tests good and backups are being made. So I tested it again about a week ago, and success - ran fine. But today copying that same job - failure.
This sounds like data integrity/consistency issues to me.
Anyway I've got a snapshot of the upgraded config if I get time to visit with support.