The 1.06 update for Cyberpunk 2077 rolled out less than a day ago now. With it comes just a couple of fixes. One of the fixes addresses the issue of save files hitting an 8MB limit which would then cause the save to become corrupt.
It seems as though this issue was only prevalent on the PC as this fix is listed as "PC specific" in the short changelog. There is also one console specific change and one more generalized fix...