PKD. Thank you for bringing this issue to our attention.

Your problem concerns a bug in the editor, which was resolved in the new release of Froala version 4.3.

According to the release, the version resolved the issue where setting fontSizeDefaultSelection in the config results in multiple wrapper divs added to the content on subsequent edits.

By updating to the new version, you can be confident that this issue will be resolved. This is the most effective solution to your problem.

After updating the version, some approaches keep your code from issues like these:

1. Check for Redundant Formatting
2. Use html.set to load content programmatically
3. Check for Cleaning Options
4. Preventing Empty Space/Line Addition
5. Dirty Check Improvement

I'm confident that these actions will fix your issue.

Please let me know if you need further assistance.