My nether base has disappeared!

Whenever i entered my portal everything has been completely resets. I lost everything in the nether. I'm also stuck in the nether. I used to have a base in the nether but after updating my Minecraft to 1.17.11 this happens. And also i spawned in where the base is built. No I didn't get teleported somewhere this is the exact spot where I've built my nether base but it strangely disappeared.