Google cloud platform app updated but associated domain not

I hosted my personal website on app engine on GCP, and added a custom domain to the app. The original url of the google app being:

https://website-263918.appspot.com/

And the associated custom domain being:

https://bozidar-vulicevic.dev/

If you open the site in a mobile view, or on smaller resolution, you will notice the logo, on the url https://website-263918.appspot.com/ will be smaller, and main font bigger, than on https://bozidar-vulicevic.dev/. This is what should be on https://bozidar-vulicevic.dev/ as well.

What do you guys think this could ? Is there a way to solve this inconsistency?