Thank you for your contacting us with this information.
May I please clarify with you if you get any error during project opening or your projects become unavailable after opening?
We got your bug reports, please tell me if these bug reports apply to your projects after moving your sandbox.
If the project is opened in The Welkin Suite and further actions on this are blocked, please open the project properties (right-click in the Solution Explorer on your project -> Properties) and refresh the Login Credentials.
I kindly ask you to let us know the result of this.