On the features site of the 3dgs website shows you: "Bones animation +weights" this is a feature for Pro users only and I have the A7 Pro.
I don't know if there are another limitations to this feature or is it just a bug.
You can't change the weights (say to maximum of 3 per bone) without change each weight number in a weights table of 3D Studio Max. If something like this is needed to get it working then it forces 3D Studio Max users to many hours/days/weeks of more work.