Thanks to the support docs and other questions here, I've made great progress in using message.extract to populate tags and extra properties fields. But I have one situation where I'm failing to extract data, my property is always blank. I'm guessing it has to do with line breaks, since my other extracts were always from a single line. I've looked at the alert from the web UI, and also exported via API, and I have regex that will match either format, but it's still not matching.
My extract string:
{{ message.extract(/SEARCH STRING(?:\\r\\n +)*\n*(\S+[^\\\n]+)/) }}
(the string I'm extracting will vary a lot, so I can't just find word "vendor", but the string "SEARCH STRING" is constant, which is my I'm trying to use that as the 'anchor' for my regex)
Description when viewed from web UI:

Description when pulled via API:

Test of regex string:

Thanks in advance for any tips!