Let me give a bit of context: I migrated my blog to a new hosting provider, when i finally exported all my posts i realized that all my images where missing. I entered to my wp-conten/uploads folder and found nothing.
What i did is to manually upload my folders with images to this folder using ftp file manager, and voliĆ my images where now displaying in my blog, i synced the uploads forlder with my media library using Bulk Media Register and everything is working fine...except for the thumbnails.
How can i re-link my broken thumbnails if i don't wanna do it manually editing post by post? I have tried Media Sync, Force Regenerate Thumbnails, and Regenerate Thumbnails plugins with no luck