@UriB,

I do not think this should really be the case looking at the specs, it should at the very least have a similar experience - but should have more efficient communications due to the jump from AC to AX Wi-Fi.

How are you testing your RE Range and Performance?

First, make sure that the RE is in a midway location, I think that the overall broadcast power is also somewhat dependent on the signal that is received and the distance from the source.

Are you able to verify that all the bands are being broadcast from the RE?

I would try to remove the device from your OneMesh configuration which should provide a few extra options fro troubleshooting, and allow you to see the true range of the different bands.

There are also setting such as Beamforming that you may consider adjusting, as they do affect the range. Beamforming is meant to increase the range, however some devices do experience difficulty with the tech.