Thunderbird UI obstructed by history popup

[jenda69]

Every time I click the Expression Search field, it pops up really wide history window which covers the top of the Thunderbird UI and the search field itself.

Once I start typing, it disappears, but it is annoying because if I try to change caret position by mouse or try to click (×) to clear the field, the history pops up again instead and I just can't do the thing I want to do. Secondly, it also covers a lot of Thunderbird UI except the tabs which are actually shown over the pop up, so it's really ugly.

I managed to somewhat solve the first issue by adding bunch of searches to the history, now the window got quite narrow and at least doesn't cover the search field...

Is there way to turn this off? I don't really need such feature anyway.