I use rustoleum and you have to be extremely patient with it… you MUST let it dry for at least a day, if not 2 before trying again.
OR
Your coats must be within 15 min of each other…
But if you are sanding, you absolutely have to wait at least 2 days…. I wait a week… then I sand… and reapply the coat
The patience pays off, as the coating is very very glossy.