Hi. I've been using the ShippingEasy app with Big Commerce for years without any major issues. A few months ago, I suddenly stopped being able to log into the ShippingEasy app inside BigCommerce. If I open a new browser window and go to shippingeasy.com, it lets me login and access my BC orders, but I can't login using the app inside BC. I have tried uninstalling and re-installing the app, but to no avail.

While I am able to sync my orders and print shipping labels at shippingeasy,com, my customers are not receiving the customized email notification that I set up in Big Commerce, which contains their tracking info and other valuable information. 

I spent a lot of time on the phone with BC customer support today and they weren't able to help me. We cleared my cookies and browsing history and tried several other things, but I still can't login. 

Has anyone experienced this problem, and if so, do you know a solution? Thanks in advance for your help.