Unexplored world/chunks are loaded as stones

All unexplored chunks in the world now render as vast stone lands (screenshot attached).

The world has been created in version 1.12.* in a dedicated Minecraft Bedrock server. The issue has been noticed in 1.14.0 client (1.14.0.9 server), but previous versions might have been responsible for the bug.

Possible duplicates:

• MCPE-56344
• MCPE-56965
• MCPE-59261
• BDS-2221