I am using the model from this website along with an imported set of teeth as the basis for an avatar I'd like to animate with shape keys. The avatar comes with a variety of shape keys that control one side of the face, and they work perfectly fine in Blender.
When I try to export those shape keys to .gltf format, however, they end up controlling the entire face (e.g. EB-angry.l controls both eyebrows, instead of just the left one as its supposed to). You can see this if you use Don McCurdy's gltf viewer. I've attempted to play around with the export settings, but to no avail. The keys also aren't distinguished in three.js, which is what I ultimately want to use to display the animations.
Does anyone have any insight into this issue? Thank you!