v79 Steals & Kills 1 of 8 Logical CPU Cores

Running an i7 3770K 4 Core (8 Logical) CPU w 32 Gb RAM on Windows 10 x64. Beginning with v79, when starting MKVToolNix GUI, it steels Core #2 (closed) from other programs (I can watch the Core #2 (closed) Usage go to zero). MKVToolNix does function normally to Multiplex a video file. When I close MKVToolNix, Core #2 (closed) never comes back from Zero Usage. Core #2 (closed) is totally dead at this point. I have to reboot to get Core #2 (closed) back and functioning as normal. All's well until I use MKVToolNix v79 again. I went back to v78 and all is well. This reported issue does not occur; I don't lose Core #2 (closed) at all. Does v79 have a CPU Affinity Issue?