Hi.
So we think we fixed the bug.
Can you please check your customers backup import into 8.4 2017.10.03 version latest build and let us know. It is available on standardinstall.com after you log in as test version.
Hi, Paul.
Sounds like you're talking about REST API. And that your are overwriting data with older values if B managed to read record before A finished to update it. Classic conflict resolution ...