Ok, no need for hiding, there she is

The F-4 FVS.
I have s problem with the VG wings. Which is when the are swepted back, they are suppose to reduce drag and make the plane fly faster. However, that doesn't happen on mine...... When the wings are swepted back, the aircarft starts decelerate as if there are more drag. Which is very frustrating.
I hope there is a solution.
Here's the link to the aircraft. All the parts are finshied and I can start putting on weapons and adding details to it after I solve this problem. Stay tuned !
https://www.simpleplanes.com/a/2go5ba/F-4-FVS