Holley 750 stalls while hard breaking

Hey guys,

im having trouble with my 750 Holley HP douple pumper, engine is a 408 stroker.
I just had it jetted and adjusted from a guy who actually knows what hes doing, car runs really great now, the only issue is that the engine stalls when i brake quite hard. I dont need to slam the breaks, its the long deceleration which causes the engine to stall. When the rpm is going down more and more while decelerating and the engine is just about to shut off, i can save it with hitting the gas.

I spoke to the guy who jetted and adjusted the carb on the phone, he thought that probably fuel floats the venturis and recommended to try lowering the secondary fuel level. Did that but no improvement.

Then I called him again and he said try to raise the primary fuel level and lower the secondary and maybe turn out the idle mixture screws 1/4 turn.
I felt turning the idle mixture screws out 1/4 turn improved the situation but didnt fully cure it.

For me it feels more like the engine is starving fuel under deceleration, as when i hit the gas it comes back, any other thoughts or ideas to this?

Greetings from Europe,
Laurin