I have a recent deployment for MR55 and have changed to the version 26.6.1 and came across below issues .
1) The roaming between the APs are not seamless and the voice calls get a really bad clarity and some times with no audio with Cisco IP phones 8821
-> We have tested the calls using the other calling applications as well and the behavior seems to be similar ( the roaming of the clients take more time than usual.
-> This behavior is observed mainly while roaming to and from MR55
-> The signal strength and the RF is checked and there is no issues found.
-> As a part of troubleshooting we have enabled a test SSID and broadcasted only on 2 APs and tried to roam between them, even that time i was recieving the oneway / no audio.
2) Intermittently random MR55 APs are loosing connectivity to the gateway.
-> Can anyone please let me know if any bugs are there related to this .
-> We have tried changing the ports and the cable.