Regular vines can generate floating inside of trial chambers when the trial chamber is in a lush cave.
A fix to MC-266625 would probably fix this as well, but personally I think lush cave decorations and sculk and such are cool things to encounter when exploring a structure so I wouldn't mind if that gets marked as intended. Floating vines, on the other hand, are clearly not intended.
Still in 24w18a.
169345152427917032
/tp 273 -8 143