I tried multi sandbox account and read this post: https://forums.developer.apple.com/thread/130456
We have the same problem for some accounts: DID_FAIL_TO_RENEW and the expiration_intent = 4 (The product was not available for purchase at the time of renewal.)
While if we tried a new account or simply buy the goods manually, it works and gives us a new transaction id.
Because of the experience, I can't test the auto subscription. I read the document and it said the transaction id is unique for buying and renewal, but I never see new transaction-id except manually buy.
Is it a regular performance?