first thing is the Logo.
Can you do the following:
1. Make sure you’re using the latest versions of the GP theme and the GP Premium plugin.
2. Customizer > General >> Structure is set to Flex Box.
3. Then go to Customizer > Site Identity and delete the Logo, publish those changes. Then re-add your logo and publish again. This should ensure the Logo has the width and height attributes thats required so the Lazyloader doesn’t mess its sizing up.