Please try to set DMZ for your PS4 on your router.

Hi 902AC is a portable router with multiple operation mode. As for your usage, Range extender mode will be fine. Also you could check the details on the website:...

You mean that you have configured Access control and only devices in the whitelist could join the normal wifi? And at the same time, you want that the devices can connect to the guest network without...

The information on the website will help you with this issue: https://www.tp-link.com/en/home-networking/mifi/m7350/#specifications

Post some screenshots of status and network map pages, and syslog is very usefull as far as I know. I believe TP-Link will be glad to help you with your issue.

I wonder that it will recover itself if not reboot it. Maybe you could move your device to the window, it has less interferance, which is good for the stable connection.