Hi, @coises, First of all, sorry for the typo. I did mean : As an example, I chose to show all lines containing the the property string, with this exact case, in the ICU.txt file ! You’re perfectly right about the bug. It occurs only when the Always hide all lines and remove Show style from text before Show command option, in the Settings dialog is unchecked After checking this option in the Setting dialog, I could easily verify, with the ICU.txt file, that the 13 green markers were there, along with the 13 lines containing the the property string I also noted that, right after you just show these 13 lines, clicking in the margin right below the line 1183 just displays the remaining lines of the ICU.txt file ! I think that behavior is normal because if you then click on the marker of the 1183 line, it then also displays all lines between lines 1164 and 1183. Moreover, if after showing these 13 lines, in the ICU.txt file, you switch to an other tab, then switch back to the ICU.txt file, this time, it also displays a triangular green marker in the last line 2132 of the file ! Finally, as you said, I could verify that the markers : Were not restored at all after a click on the Reset button which follows a click on the Expand button Were not completly restored after a click on the Reset button which follows a click on the Expand before or Expand after button Were correctly preserved if you immediately click on the Reset button However, the Show only lines with shown text in the Tools dialog seem to work properly, even after switching tabs : lines to show and markers seem preserved ! Best Regards, guy038

Please note: my removal of links above was not to claim that everyone who put in such a link was “spamming” the forum (though some may have been intended as spam); many of those links helped the original discussion prove a point, and were useful at the time. But what has happened is that bots/spammers keep seeing links to such sites, and trying to spam us with more links. We don’t want to become a link farm, so I have redacted the links, and users who are still curious can perform their own web searches to look for “fancy text generators” to generate the text or “unicode normalization” or “normalize unicode” to undo the fancy text, or use the new Unicode Normalize plugin, discussed here.

One more specific Firefox setting worth checking, since clearing your history is what started this: go to Settings > Privacy & Security, then look under “Cookies and Site Data”. If “Delete cookies and site data when Firefox is closed” is ticked, the preference cookie the theme toggle sets gets wiped every time Firefox closes, so the site can never remember your choice. The toggle itself still works for the current page load, which matches what you are seeing. Also worth ruling out: any privacy or ad-blocking extension that clears cookies automatically, and whether you are opening the site in a private window (cookies there never persist). As a quick test, toggle dark theme on, then check whether a cookie for the site exists afterwards — if there isn’t one, the browser isn’t storing it at all, which points back to one of the above.