Invisible writing

[IlTony]

Hello, I ask you for help. From a couple of days, maybe even more, when I write in chat, I don't see what I write. I'll explain. I open the chat, I write, the luminous line advances (because actually I'm writing) but I don't get out what I write (as if my writing were invisible). However, when I press enter, the message is sent and in chat I get out what I wrote. Since this is quite annoying, could anyone tell me how to solve it? Thanks in advance