Here's some detail, as someone that has worked with those machines before (internally and externally).

In the good old days the soft serve and shake machines were taken apart every night and every piece was washed and bleach-sanitized by hand. Then it was reassembled in the morning. This would leave a lot of room for error and possible contamination in the process. And the sight of a shake machine hitting full pressure with a misaligned O-ring in the barrel is a lovely one indeed.

So the newer machines take a different route: they self-pasturize. The machine goes out of service and slowly heats everything up to a bacteria-killing temperature (including the dairy mix inside), then cools everything back down to freezing temperature to serve.

This process takes about four to five hours. But if you set the clock wrong, the machine will go into its cycle at some super-inconvenient time. There are other triggers that can force a self-clean but in general it's not "broken", it's just doing this process at a bad time for you.

I'm curious how this data is being sourced. The last I checked there was an effort to put cloud-based telemetry into every unit and have them report home constantly (both to the equipment maker and to McD), but that was never intended to be public data.

EDIT: Ah, I didn't RTFT. He's using the public ordering site to scrape it (and now the title has changed). But that does mean there's some working connection from the equipment to the McCloud now. That's cool. Or maybe a manager is doing it by hand.