iOS 11.3 - Photos excessive background activity/battery drain

On iOS 11.3 - Photos is averaging 4 - 8 hours of background activity (6 minutes on screen as of now) every day, draining the battery very rapidly (I need to charge 2 - 3 times a day now).

There are other issues as well:

- When I take a new photo, it does not show in Photos/is not available to send for 15 minutes to an hour

- Photos I've taken recently show- but cannot be zoomed into / edited / or sent. Those buttons are grayed out. (they become available for those actions after a few hours)

Settings:

I'm running iOS 11.3 on an iPhone 7 with plenty of disk space.

I do have a large library (~120,000 photos) but this has not been an issue until 11.3

iCloud Photo Library: On

Optimize iPhone Storage: On

Upload to my Photo Stream: On

iCloud Photo Sharing: On

Transfer to Mac or PC: Automatic