Apparently different and not 100% compartible libraries are used on the Frontend, partictlarly in the section "Administration"
>"General">"Regular expression" and on the Server, in my example in LLD filter.
We are creating Regular expression to use with LLD filter
This regular expression verifies, and when we are testing it with the following string, it is works in Frontend as expected:
But when we are adding this expression to use with LLD filter, it doesn't work. The entries, which this expression suppose to filter-out are passing through. Re-test expression in "Regular expressions" - works, re-created LLD rule - doesn't work. The solution were to modify the regular expression. When we changed it to
it begins to produce predictable results in both, "Regular expression builder" and in LLD filter.