Probably the weather widget is loading and attempting to connect before the network has even connected, and then does not try again after some set interval after failing. The widget icon is then a question mark (in a purple circle, default breeze theme) and invoking the widget only shows the "Configure" button. I suppose it tries to connect after the set "update every" interval, but I've no idea, and that interval is typically too long anyway to get the widget to connect soon after booting/logging in.
Thanks for filing the issue. Can you describe exactly what steps you do during boot & login until you are in a Plasma Workspace with internet connection being established and what you can observe with the weather widget? The weather dataengine which in the background feeds the weather widget should react to network connection being established and then trigger an update (with 1 sec delay). Which "works for me", but obviously not at your place, thus the need for detailed description of the timeline of yours. Cmp. WeatherEngine::onOnlineStateChanged(bool) at https://cgit.kde.org/plasma-workspace.git/tree/dataengines/weather/weatherengine.cpp The state you describe is only reached for me if the actual weather data service could not be reached during network connection being on, for whateever reason. And here the weather widget surely sucks to properly reflect the state by just saying "Configure me". But let's first find what really happens for you.
I don't do anything special when I boot up, and the only process that autostarts is dropbox. If I click on the widget and select "Configure" and then adjust the update interval and apply, it connects to the internet. I usually have it set to either 30 or 31 minutes because of this, moving it up or down each login to get it to connect. I wish I could be of more help. If there are relevant logs I could attach, let me know.
Thanks for the update; changing status.
I can reproduce this on openSUSE Tumbleweed. Possible a similar issue to https://bugzilla.opensuse.org/show_bug.cgi?id=1108163.
This problem have just happened on my system. I'm using the wetter provider. Operating System: Arch Linux KDE Plasma Version: 5.17.3 KDE Frameworks Version: 5.64.0 Qt Version: 5.13.2