Autosave function can corrupt some worlds sometimes.. at least in my case. The world doesn’t save correctly last time when i already did a backup and i lost the state before at that moment. Because of this, I lost my hardcore because I fell into the void the moment I entered to the world. I had to edit the world manually to close the gap in the bedrock, but it was in vain. The gaps started to generate only on the bedrock floor... making my world impossible to live through. The only thing I've noticed is that the floor doesn't disappear if there's a building on top of it. At least that's what I've seen so far, and it's the partial "solution" to the problem, also the gaps are always generated by exposed chunks of bedrock. This bug is very serious. I don't usually report bugs here, but this happened to me even while I was in the world and recording it.
The video:
https://www.youtube.com/watch?v=lCIV7nSn0-k
Minute= 03:02:55 to 03:04:10
Timestamped link: https://www.youtube.com/live/lCIV7nSn0-k?si=mG2oExmRdQ-ViHYm&t=11026
https://www.youtube.com/watch?v=Cr7Q5b-kroU&t=4703s
The moment i fell
Minute= 01:17:00 to 01:18:40