Widgets information lost after update despite using Classic Widgets

After the update to 5.8 widgets are blocks, ok.
I installed Classic Widgets, and the format is back.

But the widgets I had in the past dissapeared
It’s a lot of information in 3 languages, images, subscription, links… so I need to recover this information before doing anything more.

Any idea how to recover that? I read about it but didn’t find any solution.

Thanks in advance.

The page I need help with: [log in to see the link]