Proplyds are not young planets, but young black holes accelerated by plasma tails.

According to Quantum FFF Theory,
Proplyds should be young molecular ( ejected star spot) black holes accelerated by plasma tails.
Proto planetary discs, show mostly a tail and seem to be in motion in opposite direction of that tail.

Why because most proplyds show strong resemblance with some Helix "proplyds". and we know that the Helix nebula is the result of a star explosion  see image:

For comparison, see the Orion proplyds below:

.In addition, The Spire / Eagle nebula is a good example of splitting and merging young starspot black holes merging into small ( micro) Herbig Haro systems producing often red dwarfs or even failed stars.
as the next Bok globule image shows.

black hole acceleration by plasma tails combined with the pairing and Herbig haro splitting process below:

The origin of micro molecular black holes as exploded ( ejected) star spot black holes.
Star spots however are assumed to be the result of crashed Comets in the former star.