Memory use exceeding preference settings

I've set the memory allocation in my preference to 18300...  but when I view my resource monitor, PS is using more of the memory than this allocation allows.  Sometimes it gets so high that it's at 95% (was at 20848 when I snapped a image of the resource monitor) and then I can't even save a file.  Why is memory running wild and not staying within the constraints of the preference settings.    I generally have to just close the app and lose my work because it completely freezes up when the memory gets this high.   I have 32G of memory on my computer and 5 more on my video card...  only Lightroom open in the background    Only have this issue with the new version of PS.   Anyone else having this memory leak issue?     And not the memory... ran diagnositic on the box a few days ago and everything came back clean.  Only happening with the new version of PS.