In looking thru additional c-span videos...seems to be a lot of places where Pres. Biden spoke w/o the seal...mostly non president stuff...
some of the places are campaign stops..florida for demmings.
Democrat party reception in PA
However, seal was there when he spoke as President on Medicare\SS\RX\
scroll down near the bottom
so maybe he can post the seal in DC, but can’t get away with it when out of the occupied district?