Lightroom Classic: Before-after comparison in Develop module

For some time I have a problem with the before-aftercomparison in the development module of Lightroom. My suspicion of something“funny” going on dates back quite some time, way before LR Classic I think.
Lately, working on images with a lot of dark tones, I got worried.

I turns out that using the before-after comparisonbetween two identical development states, the comparison shows a visual differencein the dark tones.

This is very frustrating when finetuning the dark tones in an image.


Configuration: LR Classic 7.3.1., Windows 10.