Issues with Apple ID and Purchases

Since you have already performed a fresh installation of Catalina, tried Safe Mode, signed out and back into your Apple Account, and contacted Apple Support, I would not reinstall Catalina again at this stage.

First, confirm that your Apple Account works normally on another device or through Apple's website and that your purchase history is visible. 

Then check Apple's System Status page to see whether the App Store, Apple Account, Apple Music or Apple TV are reporting an outage. Apple currently shows those services as available.

On the iMac, verify that the date, time and time zone are correct. 

Apple specifically recommends checking these when there are problems connecting to Apple services. 

Apple also recommends trying a different network, so testing the iMac through a phone hotspot would be a useful diagnostic step. (Apple Support)

You can also try signing into your Apple Account through Safari. 

If Safari works but Music, TV and the App Store do not, that gives us useful information about where the problem occurs. If Safari also cannot sign in, the investigation should include the account and network connection.

Apple's guidance for Mac App Store problems is here: If you can't download or update apps on your Mac. 

For general problems connecting to Apple services, see If you can't connect to the App Store, iTunes Store, or other Apple services.

At this point, I would not assume that Apple's servers or Catalina are responsible, and I would not erase the iMac again. 

The most useful next piece of information is the exact message or behaviour you receive when you attempt to sign in to the Apple Account on Catalina.

At this point, I would stop treating this as a normal Apple ID or password problem.

Since you can sign in to your Apple Account online, the App Store and System Preferences show you as signed in, Apple’s System Status is green, and you have already performed a completely fresh Catalina installation, the problem appears to be specifically with Apple’s media authorization on Catalina.

The strongest clue is that Music and Apple TV both give you the same generic error when you try to authorize the iMac.

Apple confirms that authorization is what allows a Mac to access purchases, and that once a Mac is authorized in one Apple media app, its purchases should be available in the other apps as well. (Apple Support)

Apple's own current guidance for problems connecting to Apple Music, Apple TV, the App Store and related services recommends checking System Status, verifying the network, ensuring the date and time are correct, trying another network, and updating macOS. (Apple Support) You have already eliminated most of those possibilities.

I therefore think it is quite possible that Catalina's older Apple media components are no longer communicating correctly with Apple's current authentication/authorization servers.

That does not necessarily mean Apple has officially declared Catalina "dead"; it could simply mean that something changed on Apple's server side and the older software is no longer handling the authentication process correctly.

A fresh installation would not fix that because it installs the same Catalina components.

The most useful test now would be to try the same Apple Account on another Mac running a newer macOS.

If that Mac can authorize successfully while your Catalina iMac cannot, that would provide very strong evidence that the problem is Catalina rather than your Apple Account.

You could also try the iMac temporarily through a completely different Internet connection, such as a phone hotspot. Apple specifically recommends trying another network for problems connecting to its services. (Apple Support)

I would also not create a new Apple Account. Your purchases are associated with the account with which they were originally purchased.

Apple specifically states that an authorized computer is required to access previous iTunes Store purchases. (Apple Support)

These are the Apple pages I would keep handy:

Apple: Authorize or deauthorize your computer for Apple Account purchases

Apple: If you can't connect to the App Store, iTunes Store, or other Apple services

Apple: Redownload music from the iTunes Store on your Mac

Apple: Download previous iTunes Store purchases in Music on Mac

So, based on everything you have already done.

 I would not keep reinstalling Catalina or repeating the standard Apple Support troubleshooting. 

The authorization failure itself is the key issue, and testing the account on a newer Mac would be the cleanest way to establish whether Catalina is the culprit.

Did you try to sign out of your Apple ID in the System Preferences/Apple ID/Overview?

Then sign in again after a restart. I had to fill in my Apple ID password a couple of times during this process, including the Lock Screen passcode for my trusted iPhone.

But after that I was able to use all Apple Services on my old MacBook Pro, Catalina 10.15.8

What do you see, if you click open the AppStore, click on your name in the left bottom corner to open the Account page and then click on "View Information"?

Do you get the option to sign into your Apple Account?

Did you try to post your question in your local Brazilian Apple Community?

Comunidade oficial de Suporte da Apple

Ingo2711 wrote:

Did you try to sign out of your Apple ID in the System Preferences/Apple ID/Overview?

Then sign in again after a restart. I had to fill in my Apple ID password a couple of times during this process, including the Lock Screen passcode for my trusted iPhone.

But after that I was able to use all Apple Services on my old MacBook Pro, Catalina 10.15.8

+ 1

An alternative , which is out side of using an older version of macOS like macOS 10.15 Catalina

And still have a usable older computer

Consider using a Linux operating system which is more modern and useable in 2026

Linux Mint 22.3

I have forgotten to mention, that I did a clean install of Catalina, downloaded and installed it directly in recovery mode, and did not use any Time Machine backup to get other data back.

How to reinstall macOS - Apple Support