Cannot move some photos between shared albums

Hello

I have a problem i cannot seem to solve on my own and can't seem to find the solution to this specific one online, maybe any of you can help me?

I am trying to move my photographs from my current (private) account to my new account (for use at the office) but I get an error (see attachment, its in Dutch tho. It says: cannot copy the photo). I'll try explaining this as specifically as possible.

What I did on my new account: I created an empty album for every project I whish to move, then shared it with the new account and gave it full access.

Then on my current (private) account: I selected all photos from an album and moved them the the empty album that is now shared with me.

The problem:  I get an error on top of the screen: could not move photos and for some reason out of the 79 pictures, only 51 got moved. When I try to move the pictures that didnt move one by one, I get the same error again with the same result. I tried this with all my other projects and got the same result: a portion of the photos gives me this error.

Anyone any Idea of what this might be?

Help would be very much appreciated.