[TxMt] TM2: moving text adds whitespace

I move text around pretty frequently using ⌃⌘[arrow keys]. There are various scenarios where moving text this way in TM2 causes the selection to expand, with whitespace inserted to the left. (Very easy to reproduce in code with different indentation levels.)

Is this known/intended? Is there a setting I’m missing that will stop it from happening?

If it’s intentional, let me say that I don’t see a use case for altering my selection simply because I moved it. :-) If the user is trying to move text out beyond the existing end of the line, I could see adding whitespace to make it work, but even then it should be added *outside* the selection without altering it, right?