Still happens in 20w30a after it should have been fixed. Also the ships do not generate at all as far as I've seen.
This should be fixed in 1.15 pre-release 3. Are you sure you weren't still on pre-release 2?
This bug is caused by chunks loading after the player has fallen down a bit and then forcing the player to start crawling. Meaning the blocks load in the same place as the player and that's why the player starts crawling.
Can be seen happening in 1.14.1 Pre-Release 2 in the following clip
This bug happened to Philza in this clip: clips.twitch.tv/SpinelessDoubtfulAlbatrossRaccAttack
It's quite a big glitch and needs to be fixed at least before 1.14.2 release.
Confirmed in 1.19-pre1.
Seed: 2271311563731694198