I stopped using the overly invasive Chrome years ago, so I have no idea what shenanigans they've been up to.

The same shenangians that Micro$oft slEdge is up to. Firefox, not so much.

Can anyone refreash me on how to fix the problem of read emails not turning red? I searched the archives but couldn't come across the fix. TIA.
Greg.

Nothing has changed at my end. It has to do with your own browser configuration and cookie files. If you periodically clear cookie files then your browser can't "remember" what you've read. Do you log in each time, or when you logged in did you place a checkmark where it says "Log me in automatically each time"? The only time I have to log in is after clearing my own cookie files. The browsers I use, Firefox and Edge, remember me across platforms whether I'm on my iPhone, laptop PC or desktop PC. I stopped using the overly invasive Chrome years ago, so I have no idea what shenanigans they've been up to.