Anvils breaking and temporarily deleting items

I was on my mate’s realm when I wanted to finally put Soul Speed 3 on my boots when once I put it on my boots dissapeared, then I relogged and I had my boots and book back but I needed it to apply so I moved my anvil, tried again multiple times but it wouldn’t work and then my anvil broke robbing me of my Soul Speed 3 and my 31 iron for my anvil.

Proof of it can be found here: https://youtu.be/FO3S5DWHoYo