CBSubs: Transaction completed but no basket created and no payment record

I've discovered 3 CBSubs transactions dating from 17/18th December with the following characteristics:

• 2 are subscription payments
• 1 is a merchandise payment
• 2 different users are associated with the 3 transactions
• The users' first names include Irish character(s), presumably unicode (this could be irrelevant, but happens to be unusual)
• All are paid using Paypal gateway
• In all cases a payment notification email was received from Paypal correctly showing item(s),  item number, invoice ID.
• There is no basket in the database for any of these transactions
• There is no record in the CBSubs payment history for these transactions

I have hundreds of transactions taking place in Nov-Jan successfully with full traceability in CBSubs. It's not obvious that there's anything special about these 3 transactions other than the minor point commented above. Here are all the CBSubs log messages for one of the two users only, comprising two transactions of which one is subscription, the other merchandise.

 

Table key 3053 is basket create and subsequent delete for the subscription. I have a Paypal notification for this with an invoice number matching the deleted basket. Why?
Table key 3074 is basket create for the merchandise. I have a Paypal notification for this with an invoice number matching the basket. Basket 3074 is clearly not in the database, yet there's no log message to say that it was deleted. Why?

 

This is rather worrying. Can you shed any light on what might have happened with these?

Sounds like the basket expired. The notification likely didn't pay the basket. Check within CBSubs > Notifications for that payment and see if the notification errored. It's possible their names being unicode is a problem if your database isn't also unicode. Ensure all your database tables and their columns have utf8mb4_unicode_ci collation to be properly compatible (this can be a problem sometimes if it was an old install migrated).