Jacques,
Based on the image you provided earlier, it seems you are using the latest app which offers location based weather station selection. If you push the button (pin icon) to the right of the location input box, you will be provided with a map showing nearby weather stations. You can tap any nearby one and select it as your location which will look something like this: pms:KATZ8903.
If you want to use a typed location, you may do so but use something such a zipcode to be more selective. This should fix the weather issue as well.
Both should also fix the weather not showing up. There is no need to factory reset and unlikely to change anything.
Let me know if that helps, thanks!