I have MR45/MR55 for my AP's that were upgraded from MR33/42 that were rock solid in the same locations.
I had a few people complain but could not really see anything on the dashboard and with it being intermittent never really saw what the issue was. But I have really noticed the issue since changing my phone from a Pixel4 to a onePlus8 pro. I can be using my phone an just suddenly network speed slows to a crawl/stop. Can be looking at a webpage or facebook etc and just will stop loading. Does not show disconnected or just respond with unable to load, instead you will sit and watch a spinning wheel forever till it timesout. Switch off the wifi and works just fine on my phones data. Turn back on wifi and it will start working again normally. Internet connection is fine and other devices both wireless and wired keep working so not an internet issue.
Happens both when in fixed location (Can be right next to AP even) and if moving around. Have also had the issue with two lenovo laptops with wifi6 so does not seem to be limited to just a single chipset or device seems more wifi6 related.
AP's currently running 27.6 firmware, have not installed the stable release or Beta yet as I don't want to add other issues into the mix. So unless someone can tell me the fix is in one of new releases I want to try and get my wifi back to being stable.
The AP's are tied into MS125-24P and a MS220-8P so being separate switches that would make it highly unlikely a switch issue causing it. The configs are basic with 3 SSID's, (two bridge mode one NAT) no VLAN's or anything special configured using default indoor RF profile with just the minimum speed set above 11 to disable 802.11b. Have not disabled the AX as that would basically defeat the purpose of going with the newer models over the units it replaced.
The health dashboard of the clients show green so its not seeing it as an obvious issue.
Hope that I can find a solution and figured I would start here before opening a support ticket as maybe its a known issue and hopefully a quick fix. I have a few dozen Aruba Go wifi6 AP22's in the field at client sites that have been rock solid and I do not have the same issue with my phone on them and no reports from anyone with the issues the MR's are experiencing.
From what I've read and seen it seems to be problems with the chipset that is used in the MR45/MR55 access points. This is a first generation 802.11ax (note, its not Wifi 6) chipset and seems to have been beset with issues, and most likely why these access points had such a sort lifespan (the MR55 is already end of sale, has been for almost a year, the MR45 is end of sale in a month).
The MR46/MR56 access points which are true Wifi 6 do not seem to have anywhere near as many issues and use a different chipset.
I know its not the answer you want, but try the power saving settings on the client and try disabling 802.1x on the APs to see if either of these make a difference. I'd also try the stable release candidate and beta firmware versions, you can always roll them back from the dashboard if they create more issues in the first two weeks (after than you can still roll back, but need to contact support).