I extended my landscape using Landscapemode>manage>add, to extend the landscape you see in the picture. then i placed road pieces on it. pressed the play button and the road pieces didn’t show up in creative. it also disappeared in uefn.
repro:
- extend your terrain using Landscape>manage>Add
- place a prop on the extended section. (I used road pieces)
- press play
Note: when you delete the extended landscape section, close uefn and reopen it. the pieces that disappeared should reappear again on both uefn and creative.