Hi Teja
I think I know where the problem is. When I created the test MCC (897-646-0211) I connected it to my existing email address which I use for production accounts. The reason I did so is because the
form to create test MCCs allows to link an existing account in the bottom yellow box (and who wants to open an extra new account if using an existing one is possible too?). So, even though my test MCC is clearly marked as "test account" in the top right, I think all the regular accounts I created below the test MCC were
not created as test but production accounts. If that
is the reason of the problem, then your account creation logic is not as stated in the help manuals, where you describe that each account created under a test MCC is a test account.
I then created another, new email address, created a test MCC for that email address and then created test accounts under that new test MCC. Suddenly my API requests to that new test account structure started to work fine.
My case would prove that this depends on the email address with which one is logged in. So, in my opinion this is wrong and should be fixed.
If the categorization of a new accounts beneath a test MCC is not determined by the parent test MCC, but by the user who is logged in, and if this is the intended behaviour, then you should update the help manuals to reflect this logic.
Otherwise, if the categorization of a new accounts beneath a test MCC should not be determined by the logged in user and just by the parent test MCC, then you should fix that in your systems.
Regards
Aleksandar