Items dissapear

Hi good evening, the reason to contact is because After a lot of effort looking for the elytras ( wings ) , I was practicing with them I have like a base over 100 high and i crashed and died on that landing base, this base is pretty big... The issue is that my wings and all the items when I died just dissapear, y come back as quickly as possible to look back for my items but there was nothing my wings, rockets , netherite peak just dissapear... At least the wing took a lot of effort to be founded to lost them just in a bug when I died... I really apreciate your help and im sorry for the bad English