Managing the Discoverability of Private Teams

I suspect that this is a mismatch in properties populated by the different routes used to create the team. The HiddenFromExchangeClientsEnabled property controls visibility for Outlook clients. Creating a MIcrosoft 365 group implies that you want to access it with Outlook, so the flag is set to false. But Teams doesn't need Outlook access, so when a team is created (and creates the underlying Microsoft 365 group), the flag ends up being set. This might have an effect on how discoverability works. Probably worth submitting a bug report to Microsoft.