Change in the Pelican Forum Display?
 

Something has changed here, at least with my Firefox browser.

(This info below is generally correct, but I'm going from memory, so a couple of minor points may be incorrect.)

Thread fonts on the main page appear to have changed, they used to be bold if I had not read the thread, then non-bold after I had read them. This is has changed recently. Something seems different as far as indicating new threads when I leave PPOT and return also.

Previously the User CP would not display threads if I had looked at them (or maybe the title was non-bold), now it even shows threads (as bold) where I am the most recent contributor....

Did something get changed on all Pelican forums? I haven't changed any settings or changed browsers...

if you click back, the bold is still there. If you renew the page or click on the forum location above the thread, the bold goes away. Nothing new. My fonts appear to be the same, I use Chrome.

Chrome seems ok. More likely your firefox has changed how it clears/saves cookies.

I have bold titles when there are posts to a thread I have not seen yet. And I think they go non-bold for threads that are older than the last time I checked in/reloaded page.

Not for me. I am refreshing. Or closing Firefox.

I have the most up to date FF, and nothing has changed for me.