I've had this issue for at least 6 months now. Happened on CU and also FCU. System will stutter and will eventually freeze when task manager is open. First indication is that the mouse gets wonky and doesn't move correctly (moves slowly and delayed).
The few times I've gotten lucky and closed task manager when the issue started happening, everything cleared up right after task manager closed.
i7 w/ 16GB RAM.
SFC and DISM are clean. Happened on CU and now FCU. Did a complete system reload on CU and FCU was a fresh install. Issue came back after each. Saw it on a Surface Pro 3 that I had before I got a new machine for the reload on CU.
Hopefully someone has an idea how to fix this.