Edit Comment Becomes to Blank Text Box

[JuSt eLLa]

When I wanted to edit a comment, all that was written had disappeared, and the text box became blank.

When I clicked "discard changes" it went back to normal.

Therefore I thought it was a display bug. I

clicked again on "edit", used the ctrl+end keyboard shortcut, and added the note I wanted.
Again, I don't see anything of what was written there before.

After saving, only the new note I added is shown.
I used ctrl+z to cancel, but nothing happened!!!

I have tried with other comments on the same card and there is no problem. It works perfectly fine.

Then I tried to edit the same problematic comment again with the only new note I added, and again, the text box became blank.

WHAT SHOULD I DO???

It seems like a specific problem in the specific comment text box.
I really need what was written there and now the data is gone.

I would appreciate any guidance and help.

[Josh_Unito]

My first recommendation would be to always save sensitive data in a back-up somewhere. If I have notes I don't want to lose, I always keep a copy in a notepad file on my laptop. 

Some browser extensions can occasionally interfere with page functionality, so I'd check which extensions you have active (if any). 

Whenever websites act a bit funny in this way, I also try to clear my cache and see if that helps or try again in a different (or incognito) browser. It's always a good idea to troubleshoot a few options like that to see where the problem's coming from. 

Unfortunately, it sounds like this is one of those classic: "turn it off then on again" IT problems.