I have experienced the same problem. When I click the cog on the very right to show a drop-down list, allowing the user to select how many weeks each navigation click jumps, the first time the user does this, (clicks on the cog, then drop-down appears, then clicks on the chevron), it shows the expanded list content on the left side of screen.
I haven't been able to correct it, but I have a workaround. Seeing as dropdowns/combo boxes use Items like galleries do, I created a small gallery to offer the same feature to the user. And it stays where it's supposed to be.