I've never seen what you describe but I have seen other data issues. It usually depends on the airline, the same types of problems occur with the same airlines.

I've asked and they say there's little they can do, the airlines systems are broadcasting this data and some airlines are better at it than others.

To be fair, it was the first majour hiccup with the app. Usually it is quite correct.

It's hard to believe airline broadcasted incorrect data in my case. Even if that was the case, they could have cross checked it with airport data, which is way easier to obtain compared to airline stream.

And also they could have additional checks for cases when aicraft "changes" departure time to 1 hr before scheduled at around 2 hours before scheduled time. It should be highly unusual case.