This Preview → Back Button behavior looks strange indeed. Not sure though if this is related to classes getting lost. But maybe you wanna have a look what’s going wrong here, @timmse:
- Create an element (e.g. a section)
- Apply a class to the section for better visibility via Style > CSS > CSS classes (I created this class via Bricks > Settings > Custom code)
- Add a heading to have some context
- Save the page
- Click the Bricks button to go to the preview (it is set to not open in a new tab)
- Check the page in the frontend → looks correct!
- Use the browser’s back button to get back into Bricks builder
- Check the builder → the section that was added before is missing
- BUT: Using the browser’s reload button at this point reloads the builder and brings back the section that was added before