Initially, I had no problem with this mesh system- amazing, high bandwidth coverage to all parts of the house.  I have Gigabit coming in.  iMac downstairs hardwired into the Deco and a switch carrying gigabit to second Deco and TV.  More recently, every device seems to be throttled to exactly 90 Mbps, even devices hardwired.  I do not have QoS "turned on" even though this model doesn't have an on/off, but followed instructions from others to remove all devices from priority and set upload and download to 1000.  No change.  Of course have rebooted everything.  I think something happened one of the times I clicked on "optimize".  Deco detects gigabit connection when I use speed test in the Deco app.  And, briefly, after reboot, I get Gigabit results from hardwired devices, but that goes away quickly as it's throttled back to 90 Mbps.

Is there no way to turn this off?  I know, someone is going to tell me "isn't 90 Mbps enough?" and, generally, it is.  But I notice the performance degradation on the hardwired desktop (this is what alerted me to something afoul).  Factory reset?  Old firmware?  Bootleg firmware?  What's the solution to get bandwidth where I want it?

Thanks in advance!