Dropped Items Disappear When Playing Cross-Platform

When dropping any items for a joined player (You are hosting on Nintendo Switch), when they drop the same or any items for you, they permanently disappear. It is impossible to recover any items they dropped. They also cannot open chests or break blocks after the glitch/bug happens. This bug happens even if they have full player permissions with no restrictions. The video I have attached is from the joined player's perspective (they are on an iPad Pro 11 from 2018 running iOS 12.4.1 using Minecraft 1.12.0). I lost diamonds to this glitch before I figured out what happened.