The browning happened at the same time as the sundew...prior to getting decent humidity....after newly transplanting....
The browning looks pretty minor to me, and its on an old leaf too, i wouldn't worry. As long as its putting out leaves, and its getting the proper light, water, etc, etc, it should be fine.
Looks like older leaves. Always look to the new growth for the health of a plant.
doent look like it gets enough sun with small traps and very green looking.
looks like a(n) old leaf just dying. normal.