ah! gravity! that makes sense. so try sitting them up more for a bit before solids maybe?
Yeah I've been trying this mad, Lilly almost hates lying down. She is constantly trying to clench her tummy so sit up so spends most of her time in her bouncer, and recently I bought her a bumbo, which she loves but cant use after a feed or she spews from the pressure on her stomach.

Shes just learnt to flip onto her stomach and the extra practise and pressure has cuased her reflux to worsen and become painful again so shes back on meds ;( heres hoping the sitting up does the trick.