Shell in trueNAS Scale, but not Core, glitch-enciphered only in Firefox

[npr]

Something strange is happening to my shell over at /ui/system/shell when I try to install a SCALE system.

* The behaviour doesn't happen on a CORE system.
* The behaviour doesn't happen on Chrome, Edge, or any Chromium based browsers, only firefox.

What you see there is the output of a simple 'ls' command. I've chopped off the right side as it contains some private information. This just shows a bunch of "-rwxr--r--", neatly aligned. Except the letters are replaced by these blocks of banded 45-degree angle lines of random colours. There's something very strange going on at the low-level rendering that's causing the shell to glitch out like this.

Obviously trying to setup ssh access for root for a new system is made rather cumbersome by having to do it blindfolded. I wonder if anyone has seen something like this and has any ideas?

This could very well be a browser bug.

 

[npr]

Here's a rosetta stone for this strange new way of writing.
Those are the ASCII characters from 0x20 up to 0x7E. (Space, which renders normally, up through the tilde "~").

Curiously: for unicode, some characters are affected, such as ë.

But others, like あ are not. Wondering if this is due to copy-paste. Trying to write

Code:

echo "あ";

will return a readable あ. But writing

Code:

echo "ë";

returns gibberish stripes.

Trying out some more unicode things:

Ж	Pass
ë	Fail
あ	Pass
π	Pass
€	Pass
➈	Pass
幽	Pass
ı	Pass
Æ	Fail
ß	Fail

Now, I happen to know that the DOS 8-bit ANSI character set for the windows computer this was tested on by default is Windows-1252. (Stuff from 30 years ago affecting modern PCs...) And every character that failed has a representation in Windows-1252. Every character that did not does not. Connecting the dots, given the couple tested characters above, I conjecture that the bug only manifests for characters in the current windows ANSI character set.

 

[UdoB]

I get this when I activate "Enable ResistFingerprinting" in Librewolf (which is basically Firefox).

Do you have some privacy enhancements enabled? Look for "block Canvas access" or similar and try disabling it...

Good luck.