Not sure how to reinstall the software. The same issue seems to occur with two H9s and it's only the undulator algorithm that has the issue. Weird. I've used the undulator algorithm a lot in the past. Not sure why it would suddenly go away – on two H9 pedals. I thought maybe there was some general setting that was wrong – but, I'm not really sure.
Connect your H9 to your PC/Mac via USB cable, and click "Pedal Settings" -> "Update stompbox's software" in H9 Control