Default Font Weight is Bold in Gutenberg

You are looking at the staging site?

That's super strange. Here is another page for example:
https://www.screencast.com/t/lfg1RtWt

Does it happen on every browser (incognito mode)?

Do you happen to have another device to test?

Hey, I fixed it! I checked your screenshots and realized that the custom font I am using is not being loaded at your end.

That means the custom font CSS is applied to Gutenberg, but the font files are not loading on your end.

On my end, I've Muli Italic installed on my Mac. That's why everything is Italic.

I installed the normal style too, and it started to look normal: https://prnt.sc/sbh4ig

In a nutshell, GeneratePress is not enqueueing the custom fonts with the Gutenberg editor. People don't report it because I guess they think it is not a big deal.

Thanks for all the time and efforts you put in helping me :)

Glad to hear that it's fixed!