CodeCatalyst - cannot associate a specific builder id with AWS Accounts when creating a space.

Apologies for the length on this - tl;dr is that in builder ID A I can't create an AWS space and associate a billing account, but switching to builder ID B allows me to create an AWS space and use the same AWS account for billing successfully.

A couple of months ago I posted that I couldn't create an alias in CodeCatalyst for a new builder ID (ID A)(https://repost.aws/questions/QUbeV0idyfTuGVG-FmnzLS0Q/cant-create-alias-in-codecatalyst) and that I'd had to create an alternate builder ID (ID B) with a different email address which did work. It was suggested that validation around the alias was possibly a little 'aggressive', and sure enough after a couple of weeks I could create an alias and I was offered the option to create a CodeCatalyst space.

However, because I had the 2nd builder ID (B) setup I just continued using that and all worked well.

Today, I wanted to switch to using the original builder ID (A) since I now had the option, so I deleted the CodeCatalyst space under the second ID (B) and made sure it was deleted from the associated AWS Account, and also deleted the associated IAM roles and then performed the following steps:

1. In CodeCatalyst space in the original ID (A), it asks me to provide a space name and an AWS account ID for billing. I do this and click the 'Verify in AWS' link, which opens a tab in the AWS Account specified and indicates a Valid Token. When I click on the 'Verify Space' button, it take me to a page titled 'Verify Amazon CodeCatalyst Space' and a message 'Account Verified, you can return to Amazon CodeCatalyst'.

2. Switching back to the CodeCatalyst tab, I now see a message under 'AWS account verification token' saying Approved, and I click on the 'Create Space' button. I do that and I'm taken to the space settings page. Opening CodeCatalyst in the AWS Console, I can also see the space in CodeCatalyst with a status of Connected in the space details, but the Billing details has a current tier of 'None tier'.

3. Back in CodeCatalyst tab, I switch to 'Billing' where it tells me I must add an AWS account for billing. Billing details show as '-' for current tier, AWS account status and AWS account name. Clicking the 'Add an AWS account button', it asks me to choose an AWS account already associated and in the dropdown I choose the account ID I specified, followed by clicking on the 'Change billing account' button. At this point I received a message saying 'An internal error has occurred whilst processing your request' and I click cancel.

4. Switching back to the AWS account tab I navigated to CodeCatalyst in the console, but now I have no Amazon CodeCatalyst spaces. I then switch back to the CodeCatalyst tab and choose the 'Add an AWS account button' again. This time it asks me to add a new account - I enter the account details and an alias and click the 'Associate AWS account' button. I get a message indicating success and too 'Finish setting up by approving the connection with AWS using your connection token xxxx-xxx-xxx-xxxx'.

5. I click on 'Complete Setup in the AWS management console' button which again asks me to verify the Amazon CodeCatalyst space. It opens up the AWS console in CodeCatalyst again and I click the 'Verify Space' button which I do and get the message telling me the account has been verified. However, switching back to the billing tab in CodeCatalyst it still shows no billing details.

6. I've also tried clicking on the 'Manage billing in AWS account' button in CodeCatalyst. This opens the AWS console in CodeCatalyst > Spaces. Opening the space, Billing details shows 'None tier' under current tier, and Allowed tier shows 'Free'. Clicking Edit, allows me to add 'STANDARD' to the allowed billing tiers but there is no way to change the current tier.

7. Switching back to CodeCatalyst shows no changes under under the billing tier, and just asks me to add an AWS account for billing.

At this stage, I delete the space, ensure it has been removed under CodeCatalyst in the AWS console and remove any IAM roles that have been created for CodeCatalyst.

If I now switch back to the second builder ID I created, I am asked to create a space but this time when I'm asked to associate an AWS account, I specify the same AWS account ID and all proceeds normally.

It seems that there is something in the configuration of the first builder ID (the one that originally couldn't create an alias) that prevents a successful association for billing.