Hello

Using Firefox, when launching the terminal from my Unraid session, a tab opens but the terminal displays like vertical lines, as shown in the picture attached.
Any ideas?

FIrefox has only Ublock Origin as extension.
Firefox 140.8ESR in Debian trixie.

Edited March 23Mar 23 by Rhain
Browser details

Does it work with a different browser?

This happens if webGl is disabled

I don't follow; please expand

I use librewolf (firefox based browser) which disables webGL by default, this is the exact output I'd get. In librewolf I add an exception for my unraid box's web gui

Far as I remember that's not default firefox behavior, but OP was using ESR release 🤷

Thanks for clarifying. That gives us another thing to check.

For the OP: open about:support in Firefox and find the Graphics section. What do the WebGL entries show, including any disabled or blocked messages? Does the terminal display correctly in another browser on the same computer?

The LibreWolf workaround is useful, but we still need to confirm whether the Firefox issue has the same cause.