[Writer] use of wildcards in Find and Replace

Hi, if I use wildcards in Find and Replace it returns “search key not found” - i’ve tried many of them, always having that same output. It’s like if it consider them as normal characters.

For example, with “^.” in Find, the first character of each paragraph should be found, instead “search key not found” is shown. Similarly, inserting “s.n” should find “son”, “sun” and so on, but again it doesn’t find anything.
Search with normal characters do work. What could depend on?

I have Libreoffice Version:

“regular expression” must be checked!