Hello

Thank you for your query. The role of "Content Font size" is exactly what you are expecting - it should change the font size of your text block content.

After changing "Content Font Size", have you saved the page and refreshed that page to check the effect? Can you remove your Joomla & browser cache then check again please?

When I change Content Font Size in the properties of a text block, nothing changes with the font size. I can only change the font size in the editor.

If you have already edited the font size via the editor, switch to code mode and clean the formatting. If you set the font size, the same as the default (16px) then nothing will change. Try another size.

Found the solution.

In the text I am using <p> tags that have their own font styling. Which overrules the styling of the component.