Number of tabs loaded in memory pattern does not work

[syldub69]

The L pattern (Number of tabs loaded in memory) does nothing in the option screen (it does not work in the "preview" field). See: http://imgbox.com/REtrFtpB Moreover the number displayed in the windows is always the same as the T pattern (=Number of tabs). So I don't understand what is exactly the L pattern.

I'm using Firefox 73.0.1 64-bit on Windows 10 64-bit.