Up until now, I wasn’t aware that Katalon actually proposes an option “match regex” with value “//div[@id=‘mat-menu-panel-(\d)’]/div/div/a[4]”. I was surprised to find a regex-like notation (\d).
I haven’t seen it before. It seems that (\d) was recently added. I haven’t ever studied it. I think, this “Regex-flavored locator” syntax is something new, and not officially documented/announced at all.
I am afraid, it could be buggy. I have an opinion that this would NEVER work, though I would not bother describing it here. If you are interested, pls have a look at my discussion at another post.
At least I would not use “match regex” as I know how to write effective XPath expressions without using regex-like things. For example, see another topic TestObject that match IP Address-like string