Time line freezes for mouse when zoomed out in the timeline with mouse wheel.

When viewing the timeline zoomed out it can not be navigated via mouse, key navigation like up-down arrow works to move the playhead, mouse cannot move the playhead.
Zoom performed with +/- keys does not trigger bug.
Zoom performed with alt-mouse-scroll triggers the bug (both left and right alt).

Once BUG is in operation, zooming in with alt-wheel at certain point triggers a minor black-screen-refresh like effect and timeline is back to normal (can use mouse to navigate).
Once bug is in effect, dbl-click any footage in project panel opens the footage in source panel - bug dissapears, timeline works.
Once BUG is in effect, any sort of timeline refresh by navigating far away left or right (home, end keys) makes the bug go away (if view changes).
Preferences setup:
Timeline Playback: Smooth Scroll
Timeline mouse scrolling: Horizontal.

Good luck.