Website Not Looking as Expected on Mobile

We have been trying to fix the issue of responsiveness on our website for the past 3 months, but it seems like the mobile version of the site keeps getting messed up no matter how many times we go through it. Whenever we fix something on one breakpoint, it seems to mess up the website on others.

We created a document containing guidelines on a responsive web design using resources from Webflow university, and the information given to us from a previous support email. Even though we have been following these guidelines, there are still many problems with the responsiveness of the website. The document can be found here: Guidelines For A Responsive Web Design | - Google Docs

It would be extremely valuable to us if you could suggest some more rules to follow so that these issues will not keep happening.

On top of that, we have also created a spreadsheet with the URLs of examples of pages that are broken in the mobile view of the website that can be found here: Sales Pages Links - ADHD Summit - Google Sheets

If you would like to take a look at it and suggest any rules to follow for the future.

Here is my site Read-Only: Webflow - Smart Course