Just got this email from Amazon
Hello,
I hope this email finds you well!
I'm writing back to you regarding our recent conversation.
I can understand your concern regarding watching videos.
It seems the the title you've given through the link is from
primevideo.com.
This was the reason you're unable to watch with using
Amazon.co.uk prime.
It seems currently that title is not available in UK.
I’ve gone ahead and forwarded your comments in the form of a feedback to the Amazon Prime Video development team.
We're always working to improve Prime Video and I appreciate you taking time to write to us about a title you’re interested in.
This would help us improve our services and features to not disappoint our customers like you.
Customer interests and feedback is always looked into at depth here at Amazon as we’re always working to improve our services to avoid disappointing our customers like you.
I'm really sorry for any inconvenience caused.
Thanks for your valuable patience and understanding in this matter.
Should you have any further questions or comments, you can reach us via the contact us link below:
www.amazon.co.uk/contact-us
We look forward to seeing you again soon.