I don't know what is affecting my wifi, generally very good, full or one off in bars, very poor 1-2 bars for AT&T. I have to turn off "switch to cell when weak wifi is detected" (interference? other?) AND use Airplane, then everything is fine.
Surprised. happens with newest iPhone and s10+ and I still think it all began after nearby lightning hit. Maybe a ISP feed or utility pole wire got compromised. I had to replace my modem, it worked but less reliably ythan it should or use to. Can't get ISP to take me seriously and test THEIR equipment first. I had their speedtest show less than 10Mbps at times, and 200Mbsec at other times. Often having to turn wifi off/on in am around 6-7 am. One should not need to reboot a router or reset modem but often on weekends I did for a couple months.
Its voodoo.