Microsoft recently announced the new MicrosoftTeams PowerShell module now include both SFBO and Teams commands, and is is no longer necessary to load both modules when operating with both SFBO and Teams features in the cloud.
This change can also be the reason why install-module MicrosoftTeams fails. I would recommend to un-install the old modules to avoid conflicts. This can be done through the computer's add/remove programs in the control panel. Alternatively use the -allowclobber switch.
Here is how to upgrade or install the new module.