Your lazy loader plugin is loading a square placeholder image, and that leads to a huge square space being reserved for your logo. Once the lazy loader gets out of the way and the correct image loads, that space collapses to the correct size, resulting in big layout shift.
which lazy loader plugin are you using ?
The plugin author should address that.
Also even with a good lazy loader, we recommend excluding the logo from lazy loading as its always above the fold. Most good lazy loaders provide a settings field where you can add a CSS Class of images you wish to exclude. for the GP logo you can use: