Charge 5 random zone minutes after exercise

[sMiik]

Did my first bike ride with the charge 5 today. I mean first actual ride, without kids, just trying to get everything out of my legs (was only 23km, though).

I did track the ride with the charge 5 (manually) and everything went smoothly but after the ride I suddenly got a notification that I got 150 zone minutes. Naturally, I was like, whoa, it certainly has been a while since I did any sport previously.

Then, a few minutes later, the charge is vibrating again. I though, its the steps this time. I was wrong. It congratulated me on my 88 zone minutes.

And once more, maybe half an hour later, it did it one more time with some number over 100 ZMs. That was maybe three hours ago, I currently have 128.

My hr is pretty high in general and stayed somewhere near 120 a while after the ride, so that explains the increase now (ok, not this much, though) but I'm still wondering about the first change when it went backwards from 150 to 88.

Anyone else experienced anything like this?

Moderator edit: clarified subject.

[JohnnyRow]

There is a default 150 Zone Minutes per week goal.  I expect that's what the first notification was - meeting weekly goal, including some previous days.