In my experience, it happens with each edit of the document, whether or not you clear the context window.

You can somewhat mitigate this, at the same moment you ask for the new edit, by adding new info or specifying the lost meaning you want to add back. But other things will still get washed out.

Nuances will drift, sharp corners will be ablated. You're doing a Xerox copy of your latest Xerox copy, so even if you add your comments with a sharpie, anything that was there right before will be slightly blurrier in the next version.

Each edit, even with unrelated edits. I had a README referring to something as "the cathedral of s*t" (some HN commentators don't care for the swearing, which is systemically bad news but w/e) and the robot would lift that phrase out in drive-bys, repeatedly.

Occasionally it would report the action, sometimes it would not bother to report it. It never reached into the README on an unrelated doc edit, but if it was touching the README, that line was getting excised.