SOLVED: backface culling option.
I am doing retopology on a model, and when I opened the file today the low poly mesh seems to hide the high poly mesh also with the backsides of the lowpoly faces.
In other words, the backside of the surrounding low poly mesh is displayed in front of the high poly mesh. I have checked the "in front"-option in object properties as I usually do, but normally its just the front sides of the surrounding mesh that hides the underlying high poly mesh. Please see video for clear example. What should I do to fix this?