Synchronization of file attachments to online account

I have a library of >9000 articles and 7.8GB in size. I am relatively new to Endnote and have been trying to synchronize my desktop account to my online account. While it is transferring the references it is not transferring the PDF attachments. I have all the attachments in my desktop library as relative links. Is it because the total size in greater than the 5GB limit? The sync status shows no attempt to transfer files, and the manage attachments tab on the online account shows no attachments. If this is the case is there a way to go beyond the 5GB limit or do I have to split my library?

In my experience, this occurs when one or more of the files exceed 100 Mb. Please consider reducing the size of the files or excluding them from EndNote. Even a single file larger than 100MB will impair attachment syncing. This is also the issue I’m experiencing. Hopefully, the EndNote (Clarivate) administrator will grant us permission to upload files larger than 100 Mb.