I was told that you don't have to buy a new licence if you have a "Permanent subscription". Which we have:

So i upgraded and when asked to entered my old licence key, which was accepted with a green tick mark:

However after submitting the licence it was rejected as invalid.

This is quite frustrating. Why pay an annual subscription if you don't even get the newest version all the time and without any trouble?
Questions:

So i upgraded and when asked to entered my old licence key, which was accepted with a green tick mark:

However after submitting the licence it was rejected as invalid.

This is quite frustrating. Why pay an annual subscription if you don't even get the newest version all the time and without any trouble?
Questions:
- Can I upgrade to Parallels Desktop 13 for Mac without additional cost?
- If yes: how is it done.