Why is the Uniform Scale reset?

Question

3ds Max

Hello!
I fasten Biped to the downloaded model. It is required to adjust the scale through the Uniform Scale. I tried to drag and set numbers in the dialogue, but it constantly resets to 100%. Maybe there is a button / checkbox that blocks it?
Thanks
PS
max.2017

Answer 1

First, one object or group must be selected (not multiple selected). Then, only the Offset scale is reset, while the Adsolute local scale remains.

Answer 2

Does not work.
Is the Biped itself subject to transformation?
I need to move my shoulders a little.
But when I release the mouse, the frame shrinks to its original size, and the value in the dialog returns to 100%