I can already say this didn't work either and is only temporary. There's been some activity in the "iOS 18 Speculation Thread," and that one is back to being stuck unread for me.I didn't even notice the "Mark forums read" button you mentioned. I just clicked it to see how that works out. I wasn't exactly keen on trying it, but figured I'd be back to normal in a month or so since the forum software appears to auto-magically show posts older than 30 days as read anyway.