I, too, have experienced this behavior from Visual Studio for the last few months, both 2015 and 2017. I have yet to find a solution; however, it seems to help when I take the time to reboot the PC every 10 to 12 debug sessions. The trouble is that I tend to get wrapped up in the task at hand, and forget to do the reboots! I assume that there is something in my PC environment that is causing this, and would love to hear of any solutions anyone out there comes up with.