Was doing someone trip mining, went to mine some iron ore with my iron pick axe. All, was fine until I went to actually smelt it only to realise it was not there. I went back to where I had found it and checked around to see if I had maybe not picked it up but it was not there. I checked my inventory just in case I had maybe used a wooden pick axe or something stupid like that but I only had and iron pick axe in my inventory. The ore had completely disappeared flm my inventory. As I was checking my inventory I realised I was also missing a stack of cobblestone I had in my inventory too. I carried on playing and I also lost some trapdoors and ladders form my inventory. This was completely random, I wasn’t throwing them out or placing them anywhere they just disappeared. Pretty annoying inconvenience.

[UPDATE]
This is not only a problem with items dissapearing form my inventory but also blocks that are broken not being dropped. I was getting some wood when I began to realise no wood was actually being dropped when I broke the blocks. It’s meant I wasn’t picking up anything. I have experimental play available to me but this particular world is not in the experimental version. I checked with mobs and when I killed a sheep it dropped the appropriate items so it seems to be a problem only with blocks