So I figured out that everything is working after pm2 restart. So first attempt after boot always has some issues, but after restart it is fine.
Thanks all for oyur help!

BTW, this is my uname -a:

Linux raspberrypi3b 6.1.21-v7+ #1642 SMP Mon Apr 3 17:20:52 BST 2023 armv7l GNU/Linux

That helped for diagnosis, partially! Correct script was executed, and log --lines showed 15. But it also throws some errors like shown here (SharedImageManager::ProduceSkia: Trying to Produce a Skia representation from a non-existent mailbox., which you also solved :-) ): https://forum.magicmirror.builders/topic/17122/sharedimagemanager-produceskia-trying-to-produce-a-skia-representation-from-a-non-existent-mailbox/2
So when disabling the gpu I can now see the graph also on the direct screen, but not the images (clouds etc.).
Gettings there…Thank you very much until here Sam!

So I figured the error at OWM out. For this module it is needed to subscribe to the onecall subscription, even though you only want to use it free of charge. So now I have the problem that the module is only seen remotely or in dev mode, but not when started by pm. Anyone have an idea about this?

Hello,
I can’t get this module to work:
https://github.com/mtatsuma/MMM-WeatherChart
In console I’m getting apiKey is invalid/401 unauthorized, but the api key is definetly correct, as it works in other modules. module configuration is exactly as on github (with the quotation marks around everything). Does someone have an idea? Can someone please share their working config.js for this module.
Thanks

@Jalibu
Thanks, that was easy. Didn’t read it the way that there are standard markers even not specified in cong.js. Didn’t check the ones specified in the example either.

Hello @Jalibu ,
When I use a position close to the center position shown in the screencast in the github readme, I always see a marker in the map, even though I have not specified any. How can I get rid of it?
Thanks