Wish I’d read your response sooner, it just happened again but I did not validate.
Here is the behavior. It looks like the issue is that it keeps trying to focus the last node that I interacted with outside of the group.
HOWEVER! This time I found a quick fix: I’m able to resolve it by group moving the other node, then returning to what I actually wanted to move.
Very strange! But now that I’ve figured out the quick fix, it’s not that painful 
Next time it happens, I will disable the plugin and report back.