Thanks, the "u" just went to the wrong column, "u matches" should not have an "u".
Btw, it would be nice if someone fluent with regular expressions could test the updated library.
Here is a list of all the supported functions:
https://regex.sorokin.engineer/en/latest/regular_expressions.html
As explained in my help, one of the options (Atomic grouping) is not supported by 'Everything', so it will not work in the search when the 'Everything' option is checked. But it will work without it, or in Lister's search.