For some reason in Houdini 20.5 when I export my mesh to an alembic file the attributes doesn´t get exported.

I'm using alembic ROP with default options to export it but when I load that exported .abc none of the attributes appear.
Anyone has this behaviour?

It works for me. You do have to unpack the pieces. I also see the Cd attribute reported by Blender.
Can you post your problem scene. I always use the ROP in the /out context, not inside /obj when I export.