I've animated rigged models in blender, and exported them as gltf with embedded materials to use for AR in aframe. They work fine, except they will disappear when they come into close proximity of the camera. I'm using the code from https://glitch.com/edit/#!/xr-spinosaurus as a base to bring them animated model into aframe 1.4.0, also using aframe-extras 7.0.0 , three.js, and the aframe-environment-component 1.3.3.
When in aframe's AR mode, the animated gltf models will disappear when I get close to them. Otherwise, they display properly.