In order to guarantee seamless transition for a registered tenant/resident you need to enter tenant's email into both old lease and the new lease. Please make sure both emails are the same on Yardi before you make the switch. You can then move the tenant to a new unit the usual way within Yardi and Property Vista will see the tenant's move. The tenant/resident will be able to see new lease information once he logs into his/her resident portal.
NOTE: If you move a tenant, you must use the Assign Unit function in Yardi to avoid any issues within the same Property