A group of Microsoft Products and technologies used for sharing and managing content, knowledge, and applications.
Hi Martin,
Thanks for your patience to wait for our updates. After consulting with more resource, it seems we can’t identify this is an expected behavior. Because In the instruction, it is said “automatically synchronized to all documents contained in
the set”. Like below.
And there’s no other built-in settings can affect that. In this scenario, we would like to suggest you create a support ticket via Office 365 Admin Center > Support. Although we want to help you till the end, however, that support team there will have the best channel to escalate this SharePoint case. To help you contact with them more easily and efficiently, I will help you write a summary. You can use this summary to leave the message and tell them the case.
I will send you a private message about the summary. You can access it via this link.
Regards,
Rena