The same thing has been happening to me with verizon for about 5 years I have gone through 15 routers they replaced the ont 5 times and the router 9, the best thing you can do is replug the ethernet in over and over again until it works. Seriously no joke plug your pc into the ont and I bet you will get the speeds you pay for but it will not go out of most routers.
Cannot use throttle control, speed test bypass, steady ping and congestion control mode keeps changing itself to auto every time I change it just restarted the router not fixed... More and more features disappear as time goes on the buttons are gone