I'm saying that the bug could be another scaling step is happening where it's not necessary. In 1x mode it could really be rendering at 1x, scaling up to 2x for whatever reason (this is the bug) and then down again.
I took fullscreen screenshots to get the statistics, then cropped via another screenshot. The first one was 2560x1440. The 2nd one was 5220x2880. So noticeably sharper.