Interesting, that shows P. domesticum with P. hastatum being a synonym. Catalogue of Life comes up with zero hits when I search for P. domesticum but there is a P. hastatum listed.
We don't have a P. domesticum listed in our database here on ATP but there is a listing for
Spade-Leaf Philodendron (Philodendron hastatum)
This one has red stems and red blush on the reverse of the leaves so I'm sure it's P. erubescens:
I went back in my computer files and this is a juvenile form of P. panduriforme:
