I’ve also been experiencing this!! I’m not sure it’s exactly a removal of forward momentum though.
As of 25w32a, on the tick where the pearl passes through the portal, it's position in the nether is what would be expected, some distance “downrange” of the portal. But, in my testing in this snapshot, advancing the game another tick causes the pearl to move left instead of forwards. I think that what looks like a removal of horizontal velocity is actually a bad coordinate transform swapping velocity vectors around.
Thomas Kane
I’ve also been experiencing this!! I’m not sure it’s exactly a removal of forward momentum though.
As of 25w32a, on the tick where the pearl passes through the portal, it's position in the nether is what would be expected, some distance “downrange” of the portal. But, in my testing in this snapshot, advancing the game another tick causes the pearl to move left instead of forwards. I think that what looks like a removal of horizontal velocity is actually a bad coordinate transform swapping velocity vectors around.