Lister search 'find as you type' issue

I have an issue where this appears to only be working intermittently.

Usually when I type the first letter the Search box comes up but is red, indicating no match even when I know there should be many matching files or folders.

Occasionaly though it does work so this is a bit baffling.

Any ideas what could be causing this behaviour?

Most probably the Sort-field specific key scrolling option, in Preferences / Lister Display Modes / Details Mode (and Power Mode). Either turn that off, or ensure the Lister is sorted by name before you start typing.

That was it, thanks.