Looks like a number of things are broken in version 1.3.0 of A-Frame, particularly when it comes to the texture pipeline. I know they deprecated a number of things, like setting texture type to RGB, but it almost looks like they deprecated everything but RGBA and there are a number of other issues as well. But if you're running into these issues, it appears that we are currently limited to version 1.2.0 for now.
Looks like a number of things are broken in version 1.3.0 of A-Frame, particularly when it comes to the texture pipeline. I know they deprecated a number of things, like setting texture type to RGB, but it almost looks like they deprecated everything but RGBA and there are a number of other issues as well. But if you're running into these issues, it appears that we are currently limited to version 1.2.0 for now.