Hi there,
There wouldn’t have been any changes made in the GP updates that would have this effect.
I just ran your site through the test and it came up Green: Page is Mobile Friendly. Sometimes the necessary stylesheets and scripts are loaded and like in my test the result is good.
What this demonstrates is the site could be optimized by combining stylesheets and javascripts into less requests. Our Optimization tips here can help with that:
https://generatepress.com/fastest-wordpress-theme/