Scenario: A word document with several paragraphs, of which only a part is to translate (the other are to translate into other languages).
Now when working on "my" segments, they are automatically populated with content from the first segments, althought these segments are not in the TM. This is a bit hilarious.
I did not test this with replacing point 4 by "Set segments as translated" but IMHO it is more logical to set them as checked to get them better "out of view" (grey segments are less intrusive than the white ones).
Auto-propagation has nothing to do with your TMs. You may as well close the TMs and autopropagation still works. Period.
Turn it off in Preferences if you find it "hilarious".
Eventually, I have found time to analyze your scenario. It seems that you wish to block auto-propagation from the group of segments. CT can block auto-propagation to the locked segments but not from them. It looks like a good candidate for the new task to block propagation from the filtered segments.