Theme preference isn't saved in Firefox

I've noticed that in Firefox (but not in Chrome) my theme preference isn't saved between page loads. I can choose the dark theme and it'll change on the spot, but refreshing or going to any other page on the site returns it to eye searing whiteness.

@lork: Hmm, I can't seem to replicate this myself. Which version of Firefox are you on? Have you tried disabling all extensions?

Sorry, I forgot all about this after a few days. It's still happening for me now on version 57.0.2 (64-bit) - Windows 10. Disabling all extensions didn't fix it.

I've been noticing this for ages too. It looks like my preference cookies are being reset every time I start a new session?

I have the same issue. Could it be related to this? It seems I'm both logged in and not:

(I manually changed back to black theme before taking screenshot)

Yeah this has started happening to me in the past couple days, I haven't changed anything with my browser. All I can think is something is up with the new Firefox version but going back to old versions doesn't fix it either. Kinda weird not being able to comment when I'm logged in, seeing the default is white background, and seeing the main page in list and not grid every time I switch pages...

It started happening to me some time ago (about 2 or 3 months) and it still happens. In my case, it happens in Chrome (version 65.0 64bits), and only happens when I am logged in.

The way I use to reproduce it is:

• Go to the main page by clicking on the top left icon (page has light theme).
• Click on the change theme icon (when not logged, it is in a popup on the user icon). Page now has dark theme.
• Click on the top left icon again (page has light theme, again)
• Open a new incognito window.
• Repeat the process (when not logged, the button is next to the "login" link)
• After I click on the top left icon to go to the main page, verify that, in the incognito window, the theme preference sticks.

As I mentioned before, it started happening around new year, and it happens in Chrome in all the PCs I have tested it. I don't have many extensions installed, and I have tried enabling them in incognito to see if one of them is causing conflicts, but none has. If you need any information about my setup let me know...