I purchased and installed a R6400v2 router in May, 2020. Shortly after, we had a lightning strike on a tree outside which damaged some of my electronics. I started having problems with my internet connection dropping intermittently. I had my ISP come in. They replace my modem and cables and connectors and it improved. However, I still periodically have problems losing my internet connection, but only for a few minutes, then it's back up. It's very intermittent. None of my neighbors are having problems. Could the router have some damage which causes it to function normally most of the time but have intermittent problems?
What you could try doing is reinstall the current firmware on the router, then factory reset it, and then do a clean install (not from backup). That'd replace the firmware if it was corrupt and would replace the old settings in case something was corrupt with them. (also why I'd recommend the clean install)
