I have had this issue for 6 months, My Archer AX55 (ver 1.6 or AX3000 4-Stream Wi-FI6 router)  just stops working.   Sometimes the internet light on it goes out (wan port)  sometimes all the lights are on like it should be.   When this happens,  you can not get to the web page for the router,  wifi doesn't work,  wired connection doesn't work.    A reboot or power cycle fixes it.  It's almost becoming a daily thing.    I did have troubles upgrading the firmware but 2 months ago, I finally got it to upgrade.   It seems to have gotten worse.  at least before it was weekly reboots but it's daily or every other day. 

Xfinity is my provider but they are not having issues.  Internet connection type is Dynamic IP, I have my own modem which is a surfboard.   I never touch it.  It's always the router with the issues. 

Do we have firmware or is it a defective router?   I also see threads with this behaviour everywhere with no answer, no help, no insight.   I hope the community hear can give more insight.   

I have not done a factory reset as of yet.   I have backed it up and its my next steps and will have to be done on the weekend.   I work from home so i have to be careful during the week doing much.

Thanks for any help.