You want to know if it is possible to connect the Microsoft Teams instance between two different tenants (Productive and Test/Development).
SAP Cloud for Customer
It is not possible to connect two C4C tenants (Productive and Test/Development) to one Microsoft Teams instance at the same time.
This behavior occurs due to the connection between Microsoft Teams and Cloud for Customer which works with cardinality 1:1.
This is the expected system behavior.
The administrator needs to have one Microsoft Teams instance for one Cloud for Customer tenant.
SAP Help Portal Link: Microsoft Teams Integration in SAP Cloud for Customer
Teams Integration, Microsoft Teams , KBA , LOD-CRM-TMS , Microsoft Teams Collaboration Channel , How To