Well we have had another PayPal order come through but not register, no email from store but in orders under incomplete. Payment gone through to PayPal though.
And that is after switching to old PayPal module so it must be something deeper.

Also keep getting this error in the logs every 2 hours from the original missing order:
2023-09-26 18:17:51 - Paypal webhook PAYMENT.CAPTURE.COMPLETED: order ID 9540
Paypal related OrderId: 89U11368WC821835M but not found in the database.

Along with this one also:
2023-09-27 5:18:46 - Unknown Error: AbanteCart core v.1.3.4 Unknown named parameter $message in <b>/home/customer/www/ourstore.com/public_html/store/extensions/default_pp_standart/storefront/controller/responses/extension/default_pp_standart.php</b> on line <b>352</b>

Going to switch back to the newer PayPal module.
Client is pulling their hair out and not happy. I have no clue what is going on with it.

default_pp_standart does not supported anymore. Please use paypal_commerce extension instead

The transaction method is Capture
Success & Captured and also Not Captured is Processing

I think they are pretty much the default tbf.

Hi,
Ah yes they are there.

But we still have the issue that no notifications are coming through when the order is placed except from PayPal, and we have had another order go missing today. It seems it is just the PayPal payments so I'm guessing it's just the new PayPal module?

I've just clicked the "Update Webhooks" button but surely that would only need clicking once after connecting the account?

I've disconnected the new PayPal module and switched back to the old one again for now as I'm getting hassled lol.

Hello.
Did you see any errors in the AbanteCart error log?

Hi again,
That may have been the case with that transaction but now we are getting more errors in the log.
Seems to be the same error repeated 4 times at different intervals, same OrderId but at different times. 4:13, 6:14, 8:14 & 10:15 so two hours apart.

2023-09-26 4:13:01 - Paypal webhook PAYMENT.CAPTURE.COMPLETED: order ID 9540
Paypal related OrderId: 89U11368WC821835M but not found in the database.

Then there is a load of raw input data after this. (if you need full log let me know)

Customer says the transactions kept failing so he then paid via credit card, but then got a confirmation that they had indeed paid with PayPal so may have possibly paid twice! For now I have disabled the new PayPal module and have reactivated the old one to see if that stops this from reoccurring whilst we figure what is happening.

Edit: Seems these error logs are related to the earlier disappearing order but the logs showed up later after I deleted the other logs. As you say, it was probably a bad DB connection for that one transaction. Client getting jumpy with this second issue being raised so I will reactivate the newer PayPal module and keep an eye on it for now.