Killed by vindicator and all items despawned instantly

I was cornered by two vindicators and a ravanger that had a pillaged riding it. I was killed in a corner of sand by a vindicator with an enchanted axe. I respawned, picked up a crossbow and killed all the remaining mobs in less than 5 mins. I got there and all my items had despawned including enchanted diamond armour and equipment as well as a stack of golden carrots. I dug out all the sand and the items were nowhere to be found except a piece of dirt and 2 dark oak planks and a birch log. It took a long time to get all those diamonds and there now gone