different original transaction id for the same subscription

"originaltransactionid" is supposed to be persistent throughout a user's transaction history for the same subscription product, or so I thought.

In a small number of our sandbox receipt samples, we notice the original transaction id changes every time the same subscription is renewed. What could be the cause of this??

Fortunately this has only happened to us in our sandbox environment so far but I would still like an answer. Here is one of our samples:
Code Block
"latest_receipt_info": [
{
"quantity": "1",
"product_id": "subscription_premium",
"transaction_id": "1000000720416586",
"original_transaction_id": "1000000720416586",
"purchase_date": "2020-09-19 06:41:05 Etc/GMT",
"purchase_date_ms": "1600497665000",
"purchase_date_pst": "2020-09-18 23:41:05 America/Los_Angeles",
"original_purchase_date": "2020-09-19 06:41:08 Etc/GMT",
"original_purchase_date_ms": "1600497668000",
"original_purchase_date_pst": "2020-09-18 23:41:08 America/Los_Angeles",
"expires_date": "2020-09-19 06:45:05 Etc/GMT",
"expires_date_ms": "1600497905000",
"expires_date_pst": "2020-09-18 23:45:05 America/Los_Angeles",
"web_order_line_item_id": "1000000035829583",
"is_trial_period": "true",
"is_in_intro_offer_period": "false",
"subscription_group_identifier": "20313162"
},
{
"quantity": "1",
"product_id": "subscription_premium",
"transaction_id": "1000000720417040",
"original_transaction_id": "1000000720417040",
"purchase_date": "2020-09-19 06:45:05 Etc/GMT",
"purchase_date_ms": "1600497905000",
"purchase_date_pst": "2020-09-18 23:45:05 America/Los_Angeles",
"original_purchase_date": "2020-09-19 06:44:35 Etc/GMT",
"original_purchase_date_ms": "1600497875000",
"original_purchase_date_pst": "2020-09-18 23:44:35 America/Los_Angeles",
"expires_date": "2020-09-19 06:50:05 Etc/GMT",
"expires_date_ms": "1600498205000",
"expires_date_pst": "2020-09-18 23:50:05 America/Los_Angeles",
"web_order_line_item_id": "1000000055817872",
"is_trial_period": "false",
"is_in_intro_offer_period": "false",
"subscription_group_identifier": "20313162"
},
{
"quantity": "1",
"product_id": "subscription_premium",
"transaction_id": "1000000720417973",
"original_transaction_id": "1000000720417973",
"purchase_date": "2020-09-19 06:50:05 Etc/GMT",
"purchase_date_ms": "1600498205000",
"purchase_date_pst": "2020-09-18 23:50:05 America/Los_Angeles",
"original_purchase_date": "2020-09-19 06:49:10 Etc/GMT",
"original_purchase_date_ms": "1600498150000",
"original_purchase_date_pst": "2020-09-18 23:49:10 America/Los_Angeles",
"expires_date": "2020-09-19 06:55:05 Etc/GMT",
"expires_date_ms": "1600498505000",
"expires_date_pst": "2020-09-18 23:55:05 America/Los_Angeles",
"web_order_line_item_id": "1000000055817910",
"is_trial_period": "false",
"is_in_intro_offer_period": "false",
"subscription_group_identifier": "20313162"
},
.... (snipped due to message constraint)
different original transaction id for the same subscription
 
 
Q