Ok, and I have just found the problem. Silly me installed the dev Gutenberg plugin from the WordPress plugin directory. Which is not needed, as Gutenberg is already within the new WordPress…
So, I uninstalled the Gutenberg plugin, and now I get no more errors.
(Didn’t want to delete this question as it might help someone else;-)
Thanks for the quick response.
I checked the settings and they both say https://www.mywebsite
It seems strange to me, because it should work?
I can try with a non https site, would that work?
