This isn’t necessarily limited to 4.11 Preview, but I’m selecting the most recent version here.
The Quick Help input at the top right works in general, but it clears the text input every time a suggestion is show. This is troublesome when you noticed that you typo’d somewhere, or think of other keywords to add when the suggestions aren’t as spot-on as they could be.
Just enter some text, wait for the suggestions to show up, then try to add more to it (or attempt to fix a typo). I can imagine this also affecting slow typers that take too long to hit the next key before suggestions show up.
Although, this seems a bit inconsistent too; sometimes the text stays while mostly it gets cleared.