Apple TV redirects priority streaming service setting

FYI: I’m using the AppleTV app on my iPhone, which is up to date on iOS upgrades.

Context:

I watch a lot of Korean series and movies in Viki that can also be watched through Amazon Prime, if you have a Kocowa add-on to your Prime account. I keep using just Viki because it has more available than just what there is through the Kocowa add-on.

Problem:

I didn’t have any problem with Apple TV until a recent iOS update. I could start watching the show or movie by choosing Viki under “How to Watch” and then any time I stop and return to continue watching, I could just select continue watching and it will open in Viki.

Now, the only way to watch through Viki is to go into the details of the movie or series episode and choose Viki under “How to Watch”. Otherwise, Apple TV will always open up the video in Amazon Prime.

Troubleshooting attempts:

1. I’ve tried unlinking Prime and Viki, closing and reopening the app and then relinking just Viki, but Prime is still there.
2. I’ve also tried to turn off and on “Use Play History” in settings while also force restarting my phone.
3. I have also gone through Apple support. We couldn’t find a solution and the extra clicking didn’t bother me much at the time. But, now it’s starting to annoy me that there is a glitch that isn’t being solved, especially since it seems that this is not an isolated problem that people have been experiencing over the past several years (from what I see in the support forums and even Reddit).

Any ideas?