Hello Francesco,
If you already have assigned the Arial font to the Body Copy in the Font Manager, it could be just a caching problem. After doing the updates and site changes, always remember to clear all caches (if you are using WP Rocket, WP SuperCache or W3 Total Cache) when updating so that the code from the latest release is always in use. This will help you to avoid any potential errors.
And please clear your browser cache too. You may use private browsing mode in testing your site to make sure that you are viewing the latest codes from the updates and not the cached version in your browser.
If nothing is helping, provide us access to your site so that we can check your settings. Please create a secure note with the following info:
– Link to your site
– WP login URL
– WP username
– WP password
– WP Administrator Role
- Confirmation that we can access and make changes to your site
To know how to create a secure note, please check this out: How The Forum Works
Best Regards.