Check your Minecraft chat settings, it's often that people have it set to "Command only", and thus do not see any outputs.
I believe I know what you’re talking about, where randomly you can’t /msg. Try logging off, turning off you’re WiFi, restart your computer and launcher, and reopen Minecraft. That should fix it.
hello, do you think it has to do something on your side rather then the servers side? because you can just try to restart your internet and turn off your computer and that should work.
If you are trying to message someone that has /ignored you, it appears you haven't messaged them at all and it hasn't worked probably so that people cant take screenshots of them messaging them and them not responding. So you should check if the person you were trying to message if they have you ignored. Hope this helped