Layout breaking

Hi

In recent days many administrators are complaining to me that theirs pages are broken by layouts. I am trying to fix them and i have noticed that they have upgraded from 6.4.1 to 6.5 or more and layout is broken or extended/wide.

After comparing diff between versions i have found out:

WP MOVED classes such as “is-layout-constrained, wp-block-group-is-layout-constrained, wp-block-cover-is-layout-constrained” from “wp-block-group”, “wp-block-cover” to “wp-block-group__inner-container” “wp-block-cover__inner-container” … WHY!?!

After that there are some CSS with !important definitions that breaks everything:

.is-layout-constrained>:where(:not(.alignleft):not(.alignright):not(.alignfull)) {max-width: none !important;}

Maybe i also missed something but this is a problem.

So my question is how to fix this?
Why and how is even possible that WP is changing classes to break previous versions!?

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