wifi dropouts on chromebook and Linux

I am having a problem with wifi dropouts on both my chromebook and my Linux computer (which are both less than a month old). I will be within about 6 feet of my (fairly new) XB8-T Xfinity router/wifi (with a direct line of sight), and it will just drop out. When I check my phone and my android tablet, the wifi seems to still be working just fine with a strong signal. This is now happening several times per day.

When I try to reconnect, my computer cannot find any wifi networks. I try turning wifi off on my computer and back on, but still no networks are found, so I am forced to restart my computer. Sometimes that works, but sometimes it doesn’t, and sometimes restarting several times does not work. I have to wait a while and restart to get reconnected.

Needless to say, this is extremely annoying. I did a search, and I see stuff about basic wifi problems (weak or blocked signal, etc.), but I did not see anything that addresses this particular problem. Does anyone have any idea what could be going on?