Luke Hiwalker4

I did some research on it, and it doesn't seem it only happens on servers, but also on mutliplayer worlds. Minimizing the game as host won't close your world, but any other player on that world will get disconnected and won't be able to rejoin until the host restarts minecraft

Thank you for your response, but that's another issue. In MCPE-19393, there appears the "disconnected from server" screen, which occurs when minimizing the windows for a longer period of time (f.E. 15 seconds). In my issue, after I minimize the game, I instantly get send to the "Generating World / loading resources", without the disconnection screen, and get to the server view again, even though I minimize the game for a much shorter period of time [in fact, one second]. I tried this in earlier versions (1.16.40, 1.16.100) on the same device and with doing the exact same thing, and this issue didn't occur on those versions.

However, this no longer seems to be an issue, I guess it got fixed in 1.16.

I had OP privileges, as you can see in the second picture. Also, cheats were activated.

I didn't even have a texture-pack (well, except the default one) when I saw this. However, it seems like it already got fixed, cause I don't see this anymore. 

Many people have this issue, and they don't even know that they are shadowmuted. However, Server owners say, its due to Mojang, and Mojang says, it's because of Microsoft/Xbox Live, and Microsoft says its because of the Servers. However, the shadowmute lays on the xbox live account, but happens when the minecraft chat filter gets triggered. Well, to unmute, you have to keep spamming A - Z then 0 - 9, each letter/number in one line on a server. Repeat this until other people can see your chat

Nobody answered, but a friend told me how to unmute myself.

Everyone who's shadowmuted: u can unmute yourself by writing the alphabet from a to z.

Then it should work again.