I am on an Amazon Fire with the latest Fire OS 126.96.36.199 and the latest Spotify 188.8.131.523.
I pay for Spotify solely because of its offline mode for when I'm traveling, so I keep Spotify in offline mode on my Fire. Whenever Spotify updates, or for some other reason I get logged out, I cannot log back in. I enter my Spotify username and password and press the Login button. It says: "You are currently set to offline. Please go online to connect to Spotify." I press the Connect button, and then it says the same exact thing. Infinite loop.
I have tried the suggested workaround of hitting the Cancel button, deleting my password, re-entering my password, and hitting the Login button again. That does not work. Same infinite loop. You mention that as a workaround but it doesn't work. I challenge you to prove me wrong.
The Spotify app should not care if it is in offline mode when processing a login request.
The only solution is to reinstall the app and redownload all the media I've downloaded for offline use, and do this every week or two.
Please reopen this issue and fix this, Spotify. This is a longstanding bug, which I'm not the only one to face.
Thanks for getting in touch with us.
This issue was already reported and we have an official thread here.
We suggest heading over there for any future updates about this.
Happy new year!