There could be a few reasons why your flexbox is not stacking properly and has a white margin on the right div block. I'll try to help you troubleshoot the issue based on the information you've provided.
1. Check flexbox settings: Make sure that the flex container div has the correct flex properties set. Check that the flex direction is set to "column" if you want the flex items to stack vertically. Also, ensure that the flex-wrap property is set to "wrap" if you want the items to wrap to the next line when the container width is exceeded.
2. Width and margin settings: Double-check the width and margin settings of your flex items. If the combined width and margin of the flex items exceed the container width, it might cause them to overflow and create a white margin on the right side. Ensure that the total width of the flex items plus any margins is less than the width of the flex container.
3. Responsive breakpoints: It's possible that the issue only occurs at certain screen sizes or breakpoints. Review the styles applied to your flexbox and flex items at different screen sizes using Webflow's responsive design tools. Make sure that the properties and values are set correctly for each breakpoint.
4. Padding and border settings: Look out for any padding or border settings that might affect the layout. These can increase the effective width of the flex items and cause them to overflow the container. Check if any padding or border is set on the container or the individual flex items that could be causing the issue.
5. Nested elements: If you have nested elements inside your flex items, such as additional divs or containers, make sure to review their styles as well. The issue may be within the nested elements rather than the flexbox itself. Check for any conflicting styles or inherited properties that could be affecting the layout.
6. Browser compatibility: Test your site on different browsers to see if the issue is specific to a particular browser. It's possible that some browsers may interpret flexbox properties differently, leading to unexpected results. Using a tool like BrowserStack can help you easily test your site across multiple browsers.
If none of the above solutions solve the issue, providing a Read-Only link to your Webflow project would be helpful in understanding the problem further. With access to your project, I can take a closer look at the specific settings and provide more accurate guidance to resolve the stacking and margin issue in your flexbox.