WMS create second tenant: "Invalid license" error

Hi!

I have a WMS 4.1.1 server with non expired PRO licenses in the isolated network. Enabled Multi-tenant. Default tenant created OK. Trying to add the second tenant using the exported license key from the WMS Cloud - no success, tried creating the Trial WMS Cloud account for the different e-mail , export license from it and use for the tenant. Still "Invalid license" error. What are the requirement for the licenses for the second and further tenants? Is it possible to test multi-tenancy with the trial licenses?