A Pre-made Minecraft Server 1.21.1 that supports Java Edition and Bedrock Edition to play in one running server. Java(PC/Laptop) players can join Bedrock users playing at PC/Laptop, Mobile Device, ...

If you put the model on item display it can be in the wrong position, you can fix this by add extra (scale * 0.5F) to the y position. That should do the trick.