if nothing else works, try deleting and reinstalling the game. i have done that a couple of times when loading was taking forever/account signing in was being broken
latest stable version 1.15.something (ie today) broken | edit: PS4
Looks alright to me; some of them are cubes and others will have a pig face etc. Perhaps the exterior will be updated later
https://www.youtube.com/watch?v=sZf2rPw_O8s this video showcases all the possible structures
this is still an issue as 1.14 (tested today)
i have managed to recreate this in a random location using spawn eggs.
if the guardians are trying to swim towards water before they fall, they continue to float in the air
I dont see anything about it no longer being an instant kill thats my bigger concern