Custom blocks gone after 1.19.20 update

After Realm upgraded to 1.19.20 custom blocks have dissappeared. However, all blocks still work in Minecraft local worlds.

Log shows this error

[Blocks][error]-Block  couldn't be found in the registry

 

I have tried to re-upload the world multiple times from the local version the works with varying results.

• No blocks in the addon work
• a handful of the blocks appear bot not all of them (maybe 10%)