Your text editor on the board, on campaign page and other places does not work properly. While usually the LEFT ALT key is used for shortcuts, your editor uses also RIGHT ALT key. The problem is RIGHT ALT+Z is working as Undo, but in Polish (this is my native language) RIGHT ALT+Z is used for producing letter "ż". I have also noticed that some other letters are not working (listed below):
ALT+A -> ą (instead makes text being in the upper index)
ALT+L -> ł (instead it changes the size of text to smaller)
ALT+Z -> described above
Only the LEFT ALT should do work as a shortcut for editor. I have noticed that you must be using the same editor as some other startup I have met some months ago. They have had the same problem until I showed them the issue and they fixed it. So it is solvable, yet I don't know the way sadly.
