I upgraded 3 of 4 3k APs at one of my sites to 4.6 the day after it was released or so and it has been a bumpy road ever since.
The primary issue has been GPS sync - Whatever fixes were in the 4.6 branch for sync don’t seem to apply to my situation. Of the 3 APs (2 3000 and 1 3000L), all lose sync at random times, for minutes to many hours. All 3 have the holdoff timer set to 864000 and occasionally exceed that timer and stop transmitting. Typically sync magically comes back a few moments after TX stops. This same issue has been present on all 3k firmware to varying degrees. It was also present on one of the APs when they were all 1k.
The secondary issue is two of the APs shedding all stations for reasons unrelated to sync loss. This started happening around the same time on both APs but doesn’t happen simultaneously on them. This has not happened on the other 2 3k APs at this site. This does not appear to be noise related, SNR and MCS rates don’t fluctuate drastically, the stations just all get shed and then come right back. This is new behavior since the upgrade to 4.6.
The third and least critical issue are alerts about the BSA being powered off and back on again. I’m unsure if this is really happening, or if it is false reporting by the APs. This happens on one of the AP a few times per day and the other once or twice per week.
I have open tickets for items 1 and 2, but nothing has come of them yet. Putting this out there to get any other feedback.