Apple Watch Ultra weather bug

I've noticed strange behaviour in the Apple Watch weather app. It's small but annoying. Here's a screenshot of my friend's Apple Watch displaying the correct weather info from today:

And here's my Ultra showing the almost the same moment, in the same district in the city:

Point being, the Ultra is not showing the temperature right: it's omitting the minus in front of the degrees (above both are set to display Celsius). The complication also gets this wrong: it's omitting the minus, showing for example 3 when it's really -3. So at a glance in the watch face the complication displays the wrong temperature.

Might not sound much, but it's actually a big thing around 0, as that's when the roads freeze etc, which is kind of why the weather app is handy.

Tested on the Ultra, noticed that altering font size makes no difference. It's still losing the minus.

Anyone else notice the same?