Why Ctrl+F in Bridge sometimes not working at all?

I created a "test" folder with a single   "test.tga".   Hit Ctrl+F and set filename>contains> test   criteria in this "test" folder.

Got  "no item to display"

It finds nothing .

What have I done wrong?   I have this weird issue  very regularly  for years alredy and on different computers.  Never figured out what's wrong.  Could somebody help please.   It's basically a single purpose  I use Bridge for. To quickly find  pictures.  For some uncertain reason  it works in  many folders just fine  but sometimes  is not working at all.