When loading this mash-up certain textures don’t load. 
So far I’ve noticed doors, torch stems and certain tree leaves not loading. 
I’ve tested this on Windows 10, iOS 13 and Nintendo Switch. 
It only occurs on my Realm. If I load the same map as a local map everything loads. I’ve tried clearing my cache, redownloading the textures. Always the same results. 

i have the latest versions of each OS and the Minecraft apps.