1929 Ford A Tudor engine stops on downhill street

[Forddan]

Hi all

I hope I can explain myself. On my 1929 Ford A Tudor , his engine stops when I brake and gear to neutral and take my feet off the clutch pedal on a downhill street. If I keep my feet pushing the clutch pedal the engine idle as expected. The car starts immediately and drive smoothly after that event. On leveled streets when I brake and take my feet from the clutch pedal the engine does not stop, as expected, all normal.

Any suggestion(s) what could be causing this issue on downhill streets ?

Thank you !