Every time I try to use the command replace-all, I can't get it to work. I enter the search string and replacement string. Then what? If I enter replace-all in the minibuffer, I see the search string highlighted. If I hit enter, the first found instance gets highlighted but not replaced. I expect that a replace-all command will in fact replace all found instances. I do know how to work through the instances one by one, but that does not require a replace-all command.
What am I missing?
Also, is it possible to search-and-replace only within a text selection? The options on the search tab seem to make the node body the smallest unit that can be search-and-replaced.