The bug
Pushing with two pistons at the same time:
the supporting block of the vine
and the second vine block
will result in floating twisting or weeping vines.
Reproduction steps
See video "The Comeback" by _MethodZz_
MC-211349
Pushing twisting or weeping vine with piston can result in floating vine
Resolved
Duplicate
0
This appears to be a duplicate of MC-197710, which hasn't yet resolved. I'd recommend attaching this video to the report as this would further demonstrate the problem. Also, if you have any additional information to provide regarding this issue, feel free to comment on the parent ticket. If you feel that this issue is affecting you, feel free to vote for the duplicated ticket, to give Mojang a basic idea of how many people are impacted by the problem. Just to further inform you, this will not determine how quickly the bug gets handled or fixed.