Pressing assigned "Jump Back" hotkey (usually Backspace) while watching a match causes crashes

On first press, everything on the map disappears and any champion / event that appears in the kill feed has a blue icon. If it's pressed again, the game will give a bug splat.

Clicking to move forward or backward in the match's timeline doesn't cause this to happen. Also, if you press the assigned hotkey once then click somewhere in the timeline, everything on the map reappears.

Here is a picture showing the champion kill announcement (you can see my tornado building up next to a Iceborn Gauntlet field because that's where I was): https://snag.gy/iwBh2m.jpg