Freeform recording not appearing on piano roll

Not sure if this is a bug or if there's something I'm missing, but I'd like to get notes on the piano roll. I recorded the notes freeform, and they're showing up on the slice mapper, but they're nowhere to be found on the piano roll, even though I've stretched it vertically as far as it will go and also quite a long way horizontally for good measure.

This is specifically with the Tiny Ocarina. I also tried with the Four Violins, and, out of a bunch of notes I recorded, two of them found their way to the piano roll.

Is this a bug, and, if not, how do I get freeform recorded notes to consistently get onto the piano roll?

Thanks!