Sandbridge beach is a little bit different than the resort area beach in Virginia Beach.
Typically trash trucks and other operational departments take to the beaches at night in the resort area and clean it up and patrol it.
That doesn't quite happen at the same frequency are strictness in Sandbridge.
Although we really don't think that it is wholly permitted (since the beach there is not considered a camping area), we highly doubt that there would be any issues with leaving a canopy set up overnight in Sandbridge. HOWEVER, leaving anything on the beach overnight would be done so AT YOUR OWN RISK.
Please understand that doing so might leave you open to vandalism or theft since the beaches aren't patrolled regularly and there are still plenty of people walking the beach at night.