I recently changed my minecraft name. when I log into a server like mineplex, and I do /friend it doesn't work. also I'll be in a call with friends, and for me it says I'm on the server, but my friends will say I'm not. Its very annoying and stressful. Sometimes my chat will get spammed saying cant connect to sign location, and just spam different chords.
/friend bug happens in 95% of the time because you are on the European server (
eu.mineplex.com) and your friends are on the American server (
us.mineplex.com) or vice versa. You can't play together, and on the friends list it shows you that your friend is offline for "13.7 seconds" and similar things. Make sure you're all on one of the two servers.