Does your router’s firmware allow you to look at the log file to see how often it is getting DHCP requests from the cameras? I am just trying to determine if the disconnects are at layer 2 (wifi) or layer 3 (internet).
If you live next to many other wifi routers, I would recommend using 20MHz channel width in the 2.4GHz band, and try to convince your neighbors to as well.
Maybe someone has a crappy microwave oven that is interfering and causing disconnects.
Or there may be someone that is intentionally using a wifi jammer that sends deauthentication frames to “competing” MAC addresses.
This isn’t a universal problem, I can connect to all 4 cameras from my Nexus 5x Android 8.0.1, using Wyze App 1.3.125 and v1 fw 184.108.40.206 and v2 fw220.127.116.11. A v1 and v2 local, and a v1 and v2 remote.
But neither is in a highly congested 2.4GHz network, and Cable internet both sites.
If you have an SD card in your cameras, you may want to capture logs from App and cameras.