Fuel lines-vapor lock

Big E
I dont think your problem is heat soak. Heat soak is a restart condition AFTER you have run it up to temp. Then when you go to restart the engine it wont start right up (because the fuel is boiling in the carb/fuel lines) and you crank for a while or have to wait for it to cool down. Then it starts right up.
It sounds like you have a carb issue or vac leak or even dirt in your tank.
Frank