Hi Eric, 

I notice that there's a line break between "PropNum:" and "208" in your output pane screenshot. It looks like a linebreak is getting captured as part of the .{4} part of your pattern. 

From this, I believe that the discrepancy you're seeing between test and runtime results is caused by a known issue (which will be fixed in Quick Fields 10) that causes the regex to run in multi-line mode during testing even though it runs in single-line mode during runtime. In multi-line mode (during testing), "." does NOT match the \n character. However, in single-line mode (and thus at runtime), the "." character matches everything, INCLUDING the \n character. 

So now the question is - how can you change the regex to work like you want it to at runtime? 

First, I recommend using \w instead of "." since as you said, you're only looking to capture "letters, numbers, or a combination of the two". I'd also double check the \n?\r? part. Most of the time you'll see \r?\n? instead. Perhaps something like Prop\r?\n?(\w{3,4}) will accomplish what you're trying to do.