The specs of my system is CentOS7 with Cinnamon GUI. I usually work with a server so I almost always have a lot of sessions of ssh -X running. If I try to do anything that will print a lot of data on my terminal my local X server freezes. The terminal does not have to be the one in use that moment and does not even have to be viewable (I am using tabs of terminals).
For more info, changing to tty2 and killing X will restart the login environment. Any other program running is not frozen (for example music playing through youtube will continue to play). Cursor is moving but nothing else can be done.
ssh -X
commands is not a good idea in the first place. Avoid-X
when it isn't strictly needed. Additionally if X was really frozen you wouldn't be able to switch to a tty.