Nathan KinkeadHelen,
I just tested it on my 2nd Gen Fire TV Stick and I was able to connect right away. Then, I realized that I was running an older version of the IPVanish app (from back when you had to side-load it). So, then I uninstalled IPVanish and searched for it on the Amazon App Store, and installed the latest version from there (much better looking interface, btw). I was able to connect with a single click of the connect button. No problems at all.
I think you really need to contact IPVanish support ([email protected]) and ask them for help. Since yours was looping over authentication, I have a feeling that there might be something wrong with your account, like it didn’t renew properly.
Despite what the previous person claimed, IPVanish has excellent support. I think that person was someone from Express VPN trying to spread rumors to send people their way.
Anyway, if you get it resolved, please let me know what it was. Thanks.