I have Prime Video thru ITunes - no longer working

I have had a Prime Video (not Amazon Prime) subscription through iTunes since at least 2017, paying $3.99 AUD p/month.

In the last 2 or so years, I’ve been unable to access it. When I log into Amazon with my iTunes email it does not recognise a subscription at all, let alone one linked to ITunes.

Apple Support has confirmed my subscription is active. I’ve troubleshooted everything Prime Video has told me to do.

In the Prime Video app, I can’t restore my purchase because my account is already in use with another Amazon account. I don’t believe I have one but would need help to find out if I’ve had one in the past.

Prime Video mentions the automatic upgrade from Prime Video to Amazon Prime when it was introduced. This excluded third party providers. Did Apple provide us with any info or options around this? Is my Prime video app that I’ve been paying for obsolete?

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