Where has search/filter by string gone?

Just upgraded to version 10.0.3266 (7060eea).

I used to be able to type in a string at the top right of the whole display, which then filtered either by email address or by a text string in the title or content. This seems to have vanished. Can anyone tell me where it’s gone? If it’s been removed completely I’ll have to change to a different email client because I use it all the time.

There are also options to filter in the message list itself.

Oops - thanks!
The greys and whites in my setup are so similar that it was almost invisibe to me! Perhaps I’ll change to different styling.

Thanks