Cannot download files from Creative Cloud with IOS device

After I synced my files with my PC to the Creative Cloud, I try accessing them/downloading them with my iPhone/iPad but it doesn't work.

In the CC app the files show up but without a thumbnail. I cannot look at them and when I try to export them it doesn't work (just showing "preparing png/mp4/jpeg" for ever).

When I access the CC from a different PC I see the files and can download them.

What can I do to get my files on my iOS devices again?