You're right. Relaxing and holding joints by clicking is disabled in 3.83.
Now you have to hover your mouse on a joint and press x instead of clicking.
Hampa said that holding and relaxing is an advanced feature, so he decided to remove it from clicking...
He also says that using z and x is faster.
And I agree with him.
If you want to get Toribash 3.8 back, download it
here.