Hello :)
You should be able to move normally.
Make sure the Host window is not minimized.
If you still see the problem, please record a video (Creating host → join → start game → show bug) so i can get a deep look at the issue :3
Viewing post in Impostor Alert Template comments
Try again but do not maximize any window, just play in windowed mode on all screens.
Check the movement group events and make sure you didn't change the events that came with the template.
If the template is working fine to you, that means you might have changed the template events, so double check.
There are no workers spawned because the host window was maximized, like i mentioned, try with all windows windowed.