Hello, I have ran multiple servers on bedrock edition and java edition in the past, and today something happened that I have never seen before. I was exploring the overworld on a bedrock server that I have been running since about the beginning of December, 2020 with my IRL friends. When I found a jungle after several hours of flying, I created a nether portal to make a base in the nether and connect it to my main base, but upon entering the nether, I found this...

On the left is old chunks, and on the right is the new chunks I generated. This server is completely vanilla, my account is the only one OP, and no one has access to console or server files. This only happened when I updated the server to the latest version, 1.16.210, earlier today. All normal blocks are replaced by stone. Water can not be placed but generates in lava's place. Riptide and swimming work fine in the water as well, so it is not ghost water. Updating the water and lava will cause an instant wall of obsidian. Hopefully this bug can be fixed soon, I do not want to have to reset my server's nether due to one glitch like this.