iPhone iPhone 6+ not uploading photos to iCloud

[negativzero]

Got a iPhone 6+, iPhone X and a 2017 MBP as well as a 200GB iCloud account. Seems like photos taken with my iPhone 6 don't get uploaded to iCloud. My iPhone X works properly on this and all my photos propagate on my other devices with no issues.

All devices are on iOS 12 b3 and Mojave b3.

 

[panar]

Same here. iOS 12 pb 2.
It worked only after I plugged in my device and started charging. The test was made with full battery.