[2.2.13] The ceiling is not interpolated when changing height via Linedef 66
It's hard to see on GIF so I suggest you look at this file: StrangeshakingwhenchangingceilingheightUDMF.wad
It's hard to see on GIF so I suggest you look at this file: StrangeshakingwhenchangingceilingheightUDMF.wad