Unable to modify QoS settings.

The bandwidth on the network was set as the result of a single speedtest run some months back, when I was facing issues. Since then, I have been unable to update the QoS bandwith or disable QoS entirely.

When I try to increase the bandwidth, I'm unable to Save. The button lights up and animates when i click it, but does not actually do anything. If i back out of that page, it asks me to confirm that I want to discard my changes. On backing out, no changes have happened and my bandwidth values are set at the old number.

If i try to disable QoS entirely, I land on a splash page suggesting that I enable it (which would imply that it is off). However, if i close that popup, and click on the QoS setting in the menu again, it takes me back to the default QoS menu with the enabled bandwidth limit.

How do i stop my entire network from being throttled due to this bug? Devices wired to my mesh network are reporting only ~295 mpbs, and when I hardwire into the modem, I'm getting my full bandwidth from the ISP - so this is clearly a Deco-level issue.