@michal Thanks for posting in our Q&A.
Not sure the specific date that MS store for business will be retired. The retirement of the Microsoft Store for Business is planned for Q1 of 2023. This date is subject to change. Currently, you can still use Microsoft Store for Business to deploy Company Portal app.
For more information about this change, here are some links can be references:
https://techcommunity.microsoft.com/t5/windows-it-pro-blog/update-to-endpoint-manager-integration-with-the-microsoft-store/ba-p/3585077
https://techcommunity.microsoft.com/t5/windows-management/faq-supporting-microsoft-store-experiences-on-managed-devices/m-p/3585286
For MS Store (New), it is a new feature in intune. For such general error code, it is suggested to create an online support ticket to check from backend and find the cause. Here is the support link:
https://learn.microsoft.com/en-us/mem/get-support
Thanks for your understanding.
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