Entire chunks specifically on those I've built on have completely disappeared. I've created the world on the PS3 Flat World Custom Setting and has since then converted it to Bedrock on the PS5. I suspect it has to do with the Caves and Cliffs Experimental setting I turned on before the update. I've created a copy of the world that still has structure in it in hopes it'll be fixed very soon. It does take 25 seconds more than usual to load the world, as if it's generating terrain yet all it does delete my 6 years worth of work.