Option dropdown list shows no background color in the Editor?

Hi there,
I don’t know if this is a bug or what. It seems like no one else is talking about this,
but I tried on different hosts, or even on try.bricksbuilder.io, and I also tried different browsers and different computers, but in all scenarios bricks builder UI is broken. The background for all dropdown options list in the builder are transparent, as shown in the screenshot.

So what seems to be the problem?
Thanks!