I need help exporting a model with all of its bones intact

export my character model as either a FBX or DAE and both file formats fail to import the armatures with their custom shapes and pose bones connected to the mesh. the bones will appear but are no longer attached to anything and also their custom shapes are also missing. Is it possible to completely export and import a rigged model with everything intact? I want to know so when I go to use Mixamo animations, I can also animate the face and eyes with my own bones and key shapes…

This is the FBX import of that exact export

The bones are all sticking out and no longer move the eyelid shape keys or the eyes. I know how to copy and paste objects from one instance of blender to another but I don’t think that will help once I’m ready to use this mesh with mixamo animations. Any help is greatly appreciated. I love Blender but I run into issues like this from time to time that I just can not solve by asking google.