File -> Settings -> Studio -> Advanced -> Use Accurate Play Solo.
Set to true, restart Studio.
Now when you run Play Solo, you will be running a “real” setup: two different data models, one server and one client. There will be a control on the Test ribbon to toggle your view between the server and client models.

Allowed the client to specify a custom teleport GUI before teleporting.

Implemented a more stable and accurate low-level constraint solver.

Fixed debugger message widget display on Mac

Fixed a bug with selecting StarterGui object in Explorer Widget in Studio.

Share Modal during open place shouldn’t crash Studio

Gui objects on scroll bars for mobile will now correctly fire input ended events when the scroll bar becomes active.

Fixed Inner Box collisions bouncing around after character death.

Fixed bug: Earlier “Seated” transition being enabled/disabled was ignored. Now, when Seated is disabled, character will not attempt to sit in seats.

Fixed PrimaryAxisOnly property of OrientationConstraint not replicating in TeamCreate.