Hi @wprsupport
Many thanks for your quick reply!
Here another screenshot from a site hosted by Infomaniak, not by WordPress: https://prnt.sc/10cbweh, same theme
The font is much bigger in the editor. WordPress thinks that the theme is impacting the size of the font in the editor.
Kind regards
Thierry
Many thanks for your reply!
In the meantime I could clarify and resolve the issue. On the site hosted by WordPress some plugins have been installed to enable the blog post. Installing them also on the other site helped to fix this!