Whenever I play on my realm I get kicked off usually about 10 seconds after I join, and I get the error message:
internal exception: java.io.ioexception: an existing connection was forcibly closed by the remote host
The problem doesn't exist whenever I play on a friend's realm or play on a server.
I have already tried reinstalling both minecraft and java, as well as restarting my computer and my router.
Environment
I use Windows 10. I have the most up to date version of Java (Version 8 Update 221 released July 16, 2019) I have a very good PC and Ethernet connection.
Thank you for your report!
We're actually already tracking this issue in MC-38565, so I resolved and linked this ticket as a duplicate.
However, that ticket has already been resolved. Depending on the resolution, that can mean that it either will be fixed in the next version, or that it is not considered a bug and won't be fixed.
If you haven't already, you might like to make use of the search feature in the future to see if the issue has already been reported.