Hello,
I have an Asus 4G-AC68U 4G router, and it is connected to an Ubiquiti USG and the USG is connected to a Cisco switch. Internet works perfectly on every device in my home except: the S95B can't connect to the app store (it can't download apps, and it can't play YouTube videos with the app), it just says "Can't connect to Samsung servers", but I can use the built-in web browser without a problem (for example I can go to youtube.com and normally watch YouTube). The PS4 can't connect to PlayStation network, but It has internet in the web browser. The Pi can connect to the internet in the web browser, it can download files in the terminal... but TeamViewer can't connect to the internet. Also I have problems with Tidal on my phone. It can't stream music without buffering while air playing, but I know my internet is fast enough (50mbps up and down).
Now here's the weird part. I took the SIM card out of the Asus, and put it into another 4G router, it didn't help. Then I tried to put that SIM card into my phone (iPhone 14 pro) and hot spotting to those devices and EVERYTHING worked! After that, I tried putting the SIM card into a portable router, and again everything worked. So I thought the USG was causing problems, so I removed it, but it didn't help.
So far I tried:
APN settings, DNS (1.1.1.1 8.8.8.8 8.8.4.4.), Static IPs, Wireless and wired connections, updating everything, exposing the devices directly to the internet with DMZ, SIM card from another ISP
What should I do?