XS1930-12HP excessive port errors at 2.5GbE speed, no errors at other speeds

Hi,

I have a XS1930-12HP. I've recently started to add some 2.5GbE devices. The first devices were three Unifi U7-Pro access points. Performance was terrible. After checking the port status on the switch I saw excessive port errors on the ports used by the access points. When I say excessive, I mean several thousand errors in a few minutes. I did some cable testing on my house structured cabling (Cat6) and did get some errors so I've purchased some new keystones so I can re-terminate them but haven't got round to doing this yet. I've set these ports to run at 1G/F and there are no (zero) port errors and this has been stable for a couple of months.

The U7-Pro's were the only 2.5GbE devices I've ever connected until I purchased a QNAP NAS. The QNAP web interface was incredibly slow and file transfers from a PC with 1GbE connection were only achieving around 3 to 15MB/s. The switch displayed port errors on the QNAP connection. If I change the switch port speed to 1G/F the port errors stop increasing, the QNAP web interface responds quickly and file transfers from the 1GbE PC are as expected at 110MB/s.

I also have a Synology NAS with a 10GbE network card. This has been running 24/7 for over a year at 10G/F (port set to Auto) and I've never seen a single error on the Synology's port. I tested it at 2.5GbE by setting the switch port speed and got the same results as the QNAP at 2.5G/F - slow web interface and file transfers at 2 to 15MB/s and several thousand port errors in a few minutes. If I set the port back to Auto and run at 10G/F, performance returns back to normal and the port errors stop increasing. I also tested the Synology at 5G/F and got no port errors.

I did have another Synology with a 10GbE card but I've just sold it. That never had any port errors at 10G/F.

So far I've tested ports 2, 3, 5, 7, 8, 9 and 10 and they all error at 2.5G/F and don't error at other speeds.
I've also downgraded the firmware to V4.80(ABQF.3) and get the same results. It's now running on V4.80(ABQF.4) again.
Hardware version is v1.2
There are no suspicious entries in the System Log.

Shall I create a Tech Support file?

Thanks