Same issue. I’ve chatted with my hosting company and they suspect it’s the php hitting max memory limits, as it’s taking lots of processing power to upload “iPhone images”.
I’ve tested this on both desktop and mobile. On desktop, when uploading multiple images, it appears as an HTTP error. On mobile, it’s the ApiError. I also got the same error on the mobile app, when trying to resyncing the posts.
Frustrated. Let me know if anyone has found a solution for it.