Keep comments as you update link to prototype
I wish you could keep comments as you update the link to a prototype. I don't believe that's possible now. It's good to be able to look back at what others have said in the past. Perhaps even being able to see the version history of a prototype that has gone through multiple rounds of feedback.
Can you help us understand the scenario that you are talking about here? Did you change the link type from it being Prototype to Design Specs, etc?
If you can share the exact steps that you followed and are not seeing comments preserved, that would enable us to help you better.
Our designers have the issue when you saved an iteration of the file (v0.02..) the comments are removed rather than persistant