I think this means that both computers signed into the project with your same account. Each user should sign in with their personal account - and obviously send/receive before signing out of one computer and signing into another. Did you create unique accounts on the server for each of you?
But I haven't used BIMcloud in years... so hopefully someone who really knows answers.
One of the forum moderators AC 27 USA and earlier • macOS Ventura 13.6.2, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB