I have shipped a few times using this service and had no issues.
You can actually track it here
https://www.trackmyshipment.co/shipment-tracking
As far as postal employees not nothing anything, that is usually the case. Most of them still don't know you can ship up to 16oz by First Class through eBay shipping.
You can see the progress in your My eBay Manage paid and shipped orders section as shown below.