+1 to Echolane’s original post. This is definitely an unsync bug. We have three devices we use Evernote on, but two primarily. We never have an issue with the three free unsyncs per month due to the infrequent switch between two of the devices.
Yesterday I tried logging in on one of the two devices with two unsyncs left. It threw a login error. When trying to access Evernote from my primary device, it then said there were too many devices. Now I can’t access Evernote from any device because a login error incorrectly used up unsyncs. It’s like it created new sessions for devices already sy