Text Formula Field returning Blank

You don't seem to have any syntax or other errors - so my first hunch might be that one of your fields is potentially corrupted and so this formula falls in line too. A more concrete example might be doing an if statement where one of the If() conditions is doing math where the denominator is 0. QB throws that as an error and the result is is can't process the rest of the formula. 

So the hunch is that one of your fields is doing a calculation that might be corrupted before this formula actually runs. So like [Billing Family Approved Total] - if that were a formula field and it was somehow undefined QB can't process beyond that as just a random point and pick example. I would suggest running a report for the records where your billing status formula is blank - and include in the report all the component fields that you're using in this formula. Check them to see if there is one with a blank value where you expect a 0 or something. You won't find a formula error for this because the actual error isn't with the formula it's the processing. So if I do [Price]/[QTY] there is no syntax error - but in your data if [qty] = 0 then the actual processing of that is impossible and it ripples into fields that might use that.