At the moment there are two types of terrain consistency issues:
1) Terrain calculation issues.
Most often those issues are solved after server restart.
2) Ground holes on server borders.
Such holes are regular on server borders but sometimes may occur in other places.
Most often then not they are client-side visual issues and can be solved with a client restart.
We are aware of the similar incidents and currently working on resolution
Please, if you encounter this bug use buttons below to vote.
Thank you, and sorry for the inconvenience caused.