Is there a source for the custom Iv’e heard of not sleeping with one’s feet towards the door?

Shalom, I’ve also heard of the custom but if there is a source, it’s clearly not found in the classic works. There’s even no mention of it in Sefer Chassidim nor Tzva’at R. Yehuda HaChasid, not in Ta’amei HaMinhagim (which includes hassidic customs), and I checked with Rav Benzion Mutzafi, and he wrote that there is no source for the custom in kabbala. Those are the places where one might have thought to find it. In short, there’s no prohibition to direct the foot of our bed towards or away from the door, for many of our grandmothers did so, but there’s clearly no obligation or source either way. With Love of Israel, Rav Ari Shvat