Apple App Store Connect
Ran into this weird quirk with the Apple App Store Connect. When adding new screenshots, it showed thumbs like it was uploaded but once clicking the submit for review it was telling me how it had images uploaded but still processing.
Next thing I see is almost all my screenshots were just grey with a cloud icon. I tried updating screenshots multiple times a day but still ran into this issue. I found this article which made me think I was seeing an error but decided to wait. After 4 hours all the screenshots are there and I was able to submit.
What I learned is Apple is looked at as the holy grail of design but this experience was less to be desired.