We are not using any resource packs or add-ons, apart from experimental features like Vibrant Visuals. I can work on getting a video uploaded whenever one of my buddies gets on so we can demonstrate it.
Still having this issue. I tried reinstalling the game (made sure to export my world because the world files did get deleted), and still can’t have my friends join the world. I’ve also noticed that my custom skin that I made of myself wouldn’t load, and I couldn’t create any skins/characters at all. I could only load the basic skins, like Steve or Alex.
Just updated to the new Bedrock Preview 1.21.90.25, and I am no longer having this issue! I got my skin back, and my friends can join my world again with no problems.