I'm using the Evernote browser version and have it open in the same browser as Trello. I've added it, linked it, checked at Evernote to see it is authorized, etc. multiple times and have done the same in Incognito browser to avoid any browser-related issues. I've tried revoking the access, disabling the Power-up, etc. and nothing is working.
When I try to access the Evernote Power-up from my Trello card, it keeps asking me to link my Evernote account.
The most recent discussions about this same topic seem to be 3-6 years ago and the suggestions did not work for me.