What does it mean exactly when you translate a video in the Polylang Pro plugin? Is it adding captions or subtitles or translating some metadata attached to the video? Can you post a link to a page on your site that demonstrates the problem?

You’re not using my video player on this page https://www.loom.com/share/88e52759ae71435ca0111973164d917e so I don’t know what kind of support I can provide.

Sorry, I didn’t understand that you had done that whole screen capture in the video. That was useful, but as always I learn more from a live page. Something in this process is duplicating the video attachments and saving them under different IDs. I suspect the translation plugin saves each translation using a different ID in the database. When you generate a thumbnail using my plugin, it is assigned to a particular video ID so when you switch languages you don’t see the thumbnail anymore because my plugin doesn’t know it’s the same video. Since the Polylang Pro plugin is a premium plugin I can’t really get under the hood and figure out how it works. If there’s any way you can find in the Polylang settings to disable that particular function I think it would solve your problem.

I’m starting to get to the bottom of the problem. All of the logic around creating thumbnails was based on the idea of unique filenames for each video. If you had saved a thumbnail but then changed your mind and generated a new thumbnail with the same filename I wanted to make sure you could replace it smoothly. But in your case if you create a thumbnail and then copy and paste the URL to another video with the same filename before the temporary files created by the plugin are cleaned up, the plugin will delete the existing attachment from the database and create a new one with the same metadata but a new post ID. It’s an edge case I never planned for but I should have a fix for it soon.

I think this was fixed in today’s release of version 4.7 but I wasn’t able to test it with the translation plugin so I’m not 100% sure.