Hi Jeff,
My recommendation is to ask that you open a support case. It feels a situation that may require us to work more tightly together with you.
Assuming I understand this correct where you have no problem logging into the add-in, you can see your saved queries but then they're not returned, and assuming rebooting the machine and restarting excel isn't helping then probably the next step should be to work together with you, learn of one specific query, then perform it via the browser using WSAPI to learn that it executes, from there, the next step may be to run the excel add-in in IE (not Chrome) and see if runs from there.
I can speculate that there may be other constraints in play here such as your IE security or network settings. Yet, normally I'd expect such issues to not allow you to login using the Excel add-in .
As said, I'd recommend you open a support case to allow us to more methodically work through this.
Thanks,
Sagi