Horizontal scroll if there are blocks with animation and 600px < as width

[Mte90]

We detect that problem, and happens on scroll not on page loading.
As I can see there is a js scroll event for AOS and removing the classes of the blocks for the animation the problem is gone.

[francgrasso]

Looks like the AOS script needs a refresh, but it is abandoned from the author. Plans are to replace the library with a maintaned and update alternative.
My suggestion, meanwhile, is to stop using "animate-" classes and switch to a plugin named Blocks Animation: CSS Animations for Gutenberg Blocks