Open Radar

 
Summary:
Sometimes, when I mark an email as unread, it reverts to read when I go to the home screen and then open Mail again.

Steps to Reproduce:
1. Set up a gmail account on an iPhone running iOS 9.3.4 (13G35) (haven’t tested in iOS 10 yet, since it’s intermittent and I’m not running iOS 10 on my primary device).
2. Get some mail.
3. Read a message, and decide you want to mark it as unread to save it for later.
4. Swipe to mark the message as unread.
5. Click the Home button to go tot the home screen.
6. Tap Mail to open it again.

Expected Results:
The message that I marked as unread stays unread.

Actual Results:
Sometimes, the message reverts to read, and stays in this loop no matter how many times I repeat the above steps.

Regression:
This may be new in iOS 9, but that’s not based on anything more than a general feeling that I didn’t see it before. It could also be related to changes in Gmail or maybe I just never noticed it, or maybe it’s something else entirely.

Notes:
Once the issue occurs, things that will fix it and make the unread status stick include:
1. Force-quitting and relaunching Mail makes the unread status.
2. Navigating to other mailboxes (I think).

Screen recording attached, and uploaded to https://cl.ly/h1Lb