Syncing problem for dropbox and sharepoint

Hello,

I have 19 PDF files, each smaller than 10 MB. The largest file is, I believe, around 9.5 MB.

For some reason, not all of the PDF files sync successfully. On the first attempt, only 10 files are synced. When I try to sync again, only total of 4 files are synced instead.

I have tried using both SharePoint and Dropbox, but the issue remains.

Is there any way someone can help me solve this issue?

Best regards,

Devanor