Hi, I am also facing exactly the same issue. Currently it is impossible to test subscription up and downgrading via the manage pages ui because it always uses the original apple account for the subscription purchase, this one actually goes through but it is then not actually renewed/updated and you simply don't get any notifications also the ui for managing the subscriptions doesn't update it simply stays the same.

Apple actually has a problem with UDP connections, i guess it has to do with reviewers being in home office via a VPN und UDP connections are blocked by their internal firewall there, but we are also facing the same problem again and again with every new version that we have to run through multiple loops in order to actually get the app through the review. It is quite sad that apple didn't resolve this problem on their end in the last year since it is happening.

We are also facing the same problem, also it seems as if price changes with a format like this: price territoryKG/territory tier26/tier /price Are accepted you even get a success response, but then later on there is no actual change in prices. If we are using this here: price territoryKG/territory tier26/tier /price price territoryKG/territory tier26/tier start_date2021-04-13/start_date keep_previous_tiertrue/keep_previous_tier /price Then we are getting also the mentioned error: ERROR ITMS-4326: "A price change cannot be made at this time. (auto-renewable price for 'subscription-30-bundle-staging01-8', territory 'ZW', start date '2021-04-13', tier '26')." at Software/SoftwareMetadata/SoftwareInAppPurchaseGroup/SoftwareInAppPurchase/SoftwareSubscriptionPriceList/SoftwareSubscriptionPrice ERROR ITMS-4326: "A price change cannot be made at this time. (auto-renewable price for 'subscription-30-bundle-staging01-8', territory 'VN', start date '2021-04-13', tier '64')." at Software/SoftwareMetadata/SoftwareInAppPurchaseGroup/SoftwareInAppPurchase/SoftwareSubscriptionPriceList/SoftwareSubscriptionPrice ERROR ITMS-4326: "A price change cannot be made at this time. (auto-renewable price for 'subscription-30-bundle-staging01-8', territory 'ZA', start date '2021-04-13', tier '52')." at Software/SoftwareMetadata/SoftwareInAppPurchaseGroup/SoftwareInAppPurchase/SoftwareSubscriptionPriceList/SoftwareSubscriptionPrice

To add to my previous comment to avoid confusion as my example actually had the same price twice, we are actually trying to update it with different price tiers :) price territoryKG/territory tier26/tier /price price territoryKG/territory tier27/tier start_date2021-04-13/start_date keep_previous_tiertrue/keep_previous_tier /price