Unable to synchronise Joplin. Giving authorisation error.

Hi, when I use Joplin and try to synchronise with Dropbox, its is giving me an error.

could not authorise application: request to api.dropboxapi.com/oauth2/token failed, reason: Please try again


In Joplin, i have selected Dropbox and and it provided me the link for authentication. When navigating to the link, I am successfully getting the code for authorisation. when i paste this link into Joplin Dropbox sync page, it waits for 5 sec or so and gives this error.