Drilling down, what I experience on a regular basis (probably weekly maybe bi-weekly) are:
(1) priority traffic throttled to a halt (talking bits per minute, bps) but not blocked, when there are no other devices competing for bandwidth.
(2) seems to stop prioritizing traffic, effectively turning off QoS (buts its still enabled).
Finally, doesn't happen as often as the other issues, but yes QoS configurations have reverted.
Regarding the UI, its really difficult to articulate the issues on this one for me. But, everything from unresponsiveness to other settings reverting randomly. I got into a habit of having to double check settings to ensure they stick.
I just kept telling myself, there will be a patch. But after a few years and two devices, finally decided to have enough of it.