TaskCollection in My Inbox App extension - Could not find property

Hello,

I have enhanced the TaskCollection Service by adding new custom properties:

These properties are available under the new metadata in backend and frontend:

I have implemented the extensionPoint where you add your additional select properties using the hook : extHookGetPropertiesToSelect

But when calling the entity from the frontend one specific property cannot be found

I have disabled cache in Developer tools and cleared cache in backend server.

Any ideas?.

Thanks,

Javier