JoZerByte,Dirty updated rt-ax88u latest alpha 1 over February 20th alpha 1. Lost wan connection. Nothing worked (restart, turn it off and back on). Had to go back to previous alpha 1.
Restart, turn power OFF/ON ... sort of does a reboot. See my case, hope it helps.
https://www.snbforums.com/threads/384-16_alpha-builds-testing-all-variants.61952/page-11#post-557673