Hi there, thank you for sharing this with us.
Unfortunately, due to how Atlassian has built the Cloud version of Confluence, certain Macros can’t be inserted into other ones. Page Properties is one of the macros that can’t be placed inside tabs.
These are some alternatives we would propose:
Use the Excerpt Include’ macro inside tabs
Use the ‘Include Page’ macro inside tabs
Please, try these solutions and, if they don’t work for your use case, contact us again and we will try to look for alternatives. If you would prefer it, we could even set up a short call to work this through.