Opening Editor preferences window while simulating and pressing Play/Stop causes memory leak

An open but minimized Editor Preferences window causes a memory leak while simulating and repeatedly pressing Play/Stop.

1. Create a blank Blueprint project. 
2. Open Editor Preferences and go to General > Performance and make sure "Show Frame Rate and Memory" is enabled. Do not minimize the preferences window.
3. From the drop down arrow next to the Play button, select Simulate.
4. Repeatedly hit Stop and Play for a while and note that memory is correctly released each time you hit Stop.
5.  Minimize the preference window and repeat step 4. Note that memory consumption climbs by appx 300MB each time you hit Play, but does not get released when hitting stop. You can repeat this until it runs out of memory and crashes, but stop short of running out so you can perform step 6.
6. Un-minimize the preferences window, then Play and then Stop. Note that most but not all of the memory that was consumed by step 4 now gets released.

Expected:

Memory should be released when clicking Stop, regardless of the state of the Editor Preferences window.

Result:

Memory is not released when stopping simulation if the Editor Preference window is open and minimized. Not an issue when open and not minimized.