I have an Iphone 12Pro and am having the same issue. I use optimum for my email through the apple mail app. I am using IOS 15.2 and my incoming emails turn to read immediately and the emails that I have saved as unread for later turn to read as well. The only thing to stop this from occurring for just a day or two is to delete the mail account and add it back in. Not only is this annoying but the fix doesn't last long. The emails are kept as unread on the optimum server so it obviously is an IOS issue. This happens when I open a notification as well as opening the app itself.
I have spent hours on the phone with Apple representatives and no one can help me...
I can't be the only one having this problem... is there a fix? This only started to happen when the last update prior to 15.2 came out...
Please help!!
thanks,
Stacey