Hi @HDN - I am not seeing any bug, I was able to download and set up the character from Mixamo and it seems to be working just fine. The geometry on the character is a bit messed up, in that the pivots of the geometry were not axially aligned to the joints, but that is a minor issue since we are talking about the animation.
The first thing to check is to make sure that you have set the Motion Extraction node on your Actor to be the same as the root joint that you set on your Actor in the Edit Settings… panel of the Asset Browser. Right-click your Actor FBX file (xbot.fbx in this case) and select “Edit Settings…”:
Then make sure you have an Actor entry on the Actor tab, and also make sure the correct root joint is selected for the root of your character:
Then once your Actor FBX import is correctly set up, make sure that the Actor in the EMotion FX Animation Editor is set up correctly as well. Select the Motion Extraction Node, which should be the same as the root bone you selected for the Actor import.
Now make sure and save your setup so that the Actor FBX has a .ASSETINFO file next to it - this file saves any data we have associated with our Actor. Then set up your Motion Set and Animation Graph as you would normally. I set up my animation graph with a couple custom parameters so that I could add conditional transition logic on my transitions and play back those animations as I wanted.
Then once I have added the logic to my transitions, checking and unchecking the checkboxes makes either the punch or the roll animation play and come back to my idle. I did not observe any roll behavior on my character as mentioned above - all animations played back correctly.
If you would like to look at some video tutorials on the EMotion FX Animation Editor, you can find a lot of helpful information. See our YouTube channel and the video tutorials, starting with the first “Getting Started Guide” tutorial for EMotion FX, which I believe is number 37:
There is also another thread on some setup for Mixamo characters here:
Hope all this helps!