JotForm Power-Up in Trello is not working

I have exactly the same problem - conclusion - JotForm doesn't work?

I have just tried authorizing JotForm account with my test Trello account and was able to create a form and submit a form submission without any issue.

Once the account is authorized with Trello, it should be displayed in the menu with Green check mark.

Could you try logging out from both Trello and JotForm accounts and close all the instances of the browser and then try logging into authorizing the JotForm account with Trello on a new window to see if that works?

Please get back to us if the issue still persists. We will be happy to assist you further.