Gutenberg paragraph font size issue since 5.7

Since updating to 5.7 I’m experiencing an issue with the small default font size for paragraph and heading Gutenberg elements: https://i.postimg.cc/fbxD01Pb/gutenberg-issue-5-7.png

Even after installing version 5.7 from scratch (plugin-less and default theme), the issue is still there.

Changing the font manually works but it would be nice to globally set a default font size for paragraphs.

Is anyone else experiencing a similar issue or has an idea on what might be causing it?