@MojangSupport My son has been unable to join servers or friends' worlds for several days, and I believe only one friend can join my son's worlds. Any tips for how to fix without losing the worlds he's built? Minecraft Android 1.18.32.02

Is he seeing any error messages when trying to join a realm/server? What troubleshooting steps has he tried so far? ^FF

Error msg is something like "Could not connect to world." Lots of troubleshooting - log out/in of MS account, restart device, different device. I even installed Minecraft on my Android phone for the first time, not connected to his account at all. I can't join featured servers.

However, I found that this is only a problem on Wi-Fi. If I use mobile data, I can connect to servers. Same if I make my phone a mobile hotspot and connect my son's tablet. Need to figure out if this is a router config problem or an ISP problem. Any tips?