Disappearing ffIterator?

I’m having an odd problem with ffIterator, and I’m hoping maybe one of you has run into something similar. Looping through a list of files, I use pub.file:getFile (using stream), and then go into a REPEAT loop with pub.flatFile:convertToValues being the first flow service called (with iterate set to “true”). On the first file called, everything runs as expected, but on the second file, ffiterator is nowhere to be found, so only the first record is parsed. Since ffiterator is nonexistent at that point, the flow branches on ffiterator=$null and exits the loop.

Does this ring bells for any of you? I can’t seem to find anything online addressing this particular situation. It’s probably a dumb mistake on my part (I’m a definite newbie!), but I’m wasting a lot of time on it, so any insight would be appreciated!