So i just figured out a way to get the QoS operational again, but only with 1.11. The process is simple.
1) Factory reset (using the router button). Keep in mind this is NOT a true factory reset from what I just discovered - very important to know.
2) Boot from Emergency Recovery Mode and load 1.11 firmware.
3) Clear cached in FF -ESL browser.
4) Go into router (default 192.168.0.1)
5) Go into router system admin/management page (GUI) and click "Restore To Factory Default Settings". This is the most important step.
6) Start router config from scratch - QoS is back.
I'm about to get an fiber (last stretch with VDSL) next Thursday. So I need to change the rates on QOS and I decided to test changing them.
And I have exactly the same problem, nothing on QOS-page saves. I cannot turn QOS off or anything. I'll try factory resetting it, when I get the line connected and will inform about my findings...
Strange thing is, if I click for it to test the bandwidth itself the numbers seem to stick (though they are not correct...), but in reality they do not stick. Reboot and there are the same numbers I put there, when I enabled QOS. There surely is something fishy here

Tested making the changes from phone (FF and Chrome), computer (FF & IE).