U6-Lite & U6-Pro - High TX Retry Rates

We rolled out Unifi across our school this week with about 95 APs, a mix of U6-Pro (60), U6-Lite (15) and U6-LR (10).

For the U6-Pros - they are great, and no connectivity issues in those rooms.
For the U6-LRs and U6-Lites, we are having connectivity issues. More than a couple people and everything slows down. Looking at Controller, it is reporting high TX Retry rates on the Lites and LRs. This is happening with all Lites and LRs, and we have tried adjusting power rates, channels, and a variety of settings. I have tried the current firmware (6.2.44), one version back (6.0.21) and the most recent beta (6.5.15). We have been unable to find any improvement with any of these adjustments.

We are primarily an Apple school (MacBooks & iPads) but there are plenty of Android phones and a few Windows machines on our network too.

Using a few spares, we exchanged a Lite, and 2 LRs for Pros. In the same room, with the channel and power settings on Auto, we have no issues in both locations. This makes me think there is something different in how the Lite/LR’s operate.

U6-Lite/LR TX Retry rates are between 70 and 95%
U6-Pro TX Retry rates in the same rooms are less than 10%

For now, we are using our spare Pros where possible, and we have reinstalled Meraki units in some spaces.

Has anyone experienced something like this before?

Thank You!

Nick

How many devices are trying to connect to those?

@LTS_Tom
Between 15-20 devices connected on many of the Lites and LRs, and I’ve seen as high as 50 on the LR, but with the majority of users reporting issues with website loading.