In the scenario described, I would not expect a new transaction as the subscription would still be _active and therefore still has service. When a customer cancels their subscription, they retain service until the end of their current transaction period (expires date) but their auto-renew state is set to false.
Therefore the only event you would receive in this scenario via App Store Server Notifications is the DID_CHANGE_RENEWAL_STATUS indicating that auto-renew state change when they canceled and if they re-enabled it via your "resubscribe flow".
But I would argue why did the customer need to "resubscribe"? Ideally your app only indicated they were going to expire on their expires date and that by resubscribing they would be re-enabling the subscription to auto-renew. Typically customers are retained when presented a subscription offer (promotional offer or offer code) that encourages them to stay. Check out our Proactive Restore best practice session: https://developer.apple.com/videos/play/wwdc2022/110404/
While we are concerned with the comment that you didn't receive a server notification, please confirm the subscription was still active and auto-renew was disabled (via renewal info) when you resubscribed. If you file a feedback assistant ticket, reply with that # here and se sure to include the sandbox Apple ID and verify your server notifications configuration (version and url) and that others notifications were received in your ticket.