Troubleshooting of ebay-magento connector

I have been using an extension from webkul, called multi-store ebay magento connector
This extension uses eBay APIs to:
1. Upload/update products, prices and inventory
2. Nightly update exchange rates and recalculate ebay store prices
3. Pick up ebay orders and create magento orders
4. Following new order creation, the system will automatically update the inventory of all ebay stores to the default qty configured for the products ordered.

Function #3 and 4 stopped working on 8th January.
No on-screen error message, but perhaps in the log file.
My suspicion is that ebay has upgraded its API dealing with orders, as even the manual importing of ebay orders has failed since 8th January
Mission
To undertake a review of the functionality that deals with picking up and processing ebay orders.
1) Find an review the log to see why this function has failed since 8th January.