Something wonky is happening - new post appearance disappearing

Just today I'm finding that when I first go into a category, everything looks fine - I can tell which threads have new posts, which don't. But once I go into any thread and then back out to the category page again, every single thread in the category suddenly appears as fully read. And it stays that way, even when I leave the category and go back in. Weird. Can you please have a look into it?
With all its sham, drudgery, and broken dreams, it is still a beautiful world. Be careful. Strive to be happy. ~ Desiderata
Post edited by PJ_Soul on
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Prague Krakow Berlin 2018. Berlin 2022
EV, Taormina 1+2 2017.
I wish i was the souvenir you kept your house key on..
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Not today Sir, Probably not tomorrow.............................................. bayfront arena st. pete '94
you're finally here and I'm a mess................................................... nationwide arena columbus '10
memories like fingerprints are slowly raising.................................... first niagara center buffalo '13
another man ..... moved by sleight of hand...................................... joe louis arena detroit '14
"...I changed by not changing at all..."
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