Screenshots blurry upon upload

Hello!

I have an issue only with my screenshots. I use a Mac and when I take a screenshot it comes out crisp and sharp. However, as soon as I upload it to the WordPress image library it becomes blurry, and upon posting it on my Astra site it is blurry as well (as you can see with the one screenshot on the page I posted. It is the Google Flights/map screenshot.)
I do not have any image optimizer set to compress images upon upload, I do that only when I am done an article and ready to optimize everything and publish. I also contacted my webhost just to see if the problem could be something under the hood, but they said everything looks fine. They said it looks like somehow WordPress is compressing the file upon upload.
So, I’m not sure if the issue is with WordPress or the Astra theme, but I’m hoping someone can help.
Thank you so much for your help in advance!

The page I need help with: [log in to see the link]