This is also effecting things you place like Signal Boosters and Save Beacons, they phase through the ground and dont adhere to the ground terrain.
Luckily you can turn free placement on and have them half buried in the ground or floating in the sky, so still placeable somewhat.
The save beacon I placed this way I was unable to delete, recolour or move in the build mode editor, it could be picked up as normal.
Edit:
Okay it’s all build items, base computers, floors, none of it adhering to surface, all free floating.
Good time to go build a base on surface of a water system actually 
just remember, the bug also prevents you from deleting items 
Update:
@Mad-Hatter @Polyphemus after closing the game down and returning later, all of the above issues had ceased. I can place Exocraft/build items again. If it happens again a restart might do the job