Hi,
Thanks for the additional information.
From your description, the issue still appears to be related to browser caching, as it only affects Microsoft Edge users who visited the site before the upgrade.
Unfortunately, SP Page Builder does not provide a feature to remotely clear or invalidate the browser cache of returning visitors. Once a browser has cached older assets, it is up to the browser or the server's cache headers to determine when those files should be refreshed.
Could you please let us know whether you are using any server-side caching, a CDN (such as Cloudflare), or any optimization plugins? These can sometimes continue serving older JavaScript or CSS files after a major upgrade.
However, you may try to use purge css option in SPPB settings to see if it helps!
https://cleanshot.com/share/MNHjNKZL
Here is the related documentation:
https://www.joomshaper.com/documentation/sp-page-builder/settings#advanced
If possible, please also provide temporary Joomla administrator access so we can review your site's caching configuration and investigate whether anything is preventing the updated assets from being served correctly.
Best regards,