Armature doesn't properly import to Roblox Studio

The bones for arms and legs won’t properly import to Roblox Studio.

This is how it looks in blender:

And here it is in Roblox Studio:

I noticed that only the bones that are parented with “With Automatic Weights” work, and not the ones with “Bone”. I don’t want to use automatic weights for the whole character since that will deform it. Any idea what I can do?