I've never seen these before. Maybe there will be someone that has. In the meantime I did some searching for you and found 2 different manufacturers that had a cable type actuator like yours.
This one may be what you have. It's an American Standard Sink Pop-up Drain Stopper (Speed Connect Drain) and the link for the video is here. After watching the video, I'm not sure how of if it's adjustable. Just appears to be a correct or incorrect way to assemble it. Although I suppose if it got worn out or broken it could leave your stopper in the down(closed) position.
I hope this helps.
One was by a company called FRANKE, I believe. I have attached a video for that one but there is no sound. I believe it would be in a different language, if there was sound. But if by chance you have this type I believe you would know. Although it appears to be for a kitchen drain.
Let me know how you make out.