YouTube Channel Subscription

Hi, I'm trying to 'change' my 'level' of membership on a Youtube channel.

Although the new membership option is visible on my computer, I cannot see it on my iOS device.

On the computer, it says: "You can change to this level from the YouTube iOS app."

I've purchased my first membership on App Store without issues, but now, I cannot upgrade it.

Log out and re-log in to the YouTube iOS app not working. Canceling the existing subscription through Apple Store not working... Can you point me to the right solution?

Thank you!