Unable to configure Amazon Account thing (Amazon Echo Control Binding)

Hello! New openHAB user here, so please pardon any obvious wrong-headedness.

I was able to add several Z-Wave devices to openHAB, but was unable to sign in with my Amazon credentials in order to configure the Amazon Account thing from the Amazon Echo Control Binding.

Steps to reproduce:

  1. Add Amazon Echo Control Binding from Add-ons in PaperUI
  2. Inbox->±>Amazon Echo Control Binding->Add Manually->Amazon Account
  3. Visited openhab:8080/amazonechocontrol/[ID]
  4. Entered Amazon credentials
  5. Page hangs (no glyphs or errors as in other posts). Browser says “Waiting for fis-na.amazon.com” in the status line

A few observations:

  • I didn’t see any relevant messages in the openhab, event, or audit logs
  • My Raspberry Pi is connected to the internet and can successfully ping fis-na.amazon.com

Did I just do something silly? Any pointers would be much appreciated!