Logged back onto realm and my entire inventory was missing including 24lvls

This is now happened to both myself and my brother in the realm we rent, but the bug hit him first. he logged back on a day after doing a normal save and quit procedure to find that his entire inventory was missing, he had lost all but 7 of his experience levels and was back at spawn point. I was playing with him when he discovered this and we wrote it off as he must've left AFK and died. Until it happened to me 2 days later. Together we have lost enchanted netherite armor and tools as well as full inventories full of shulker boxes and supplies. What causes this issue? And what are the chances out items could be restored? Any help we would greatly appreciate.