Users are getting an error

Using the latest version of WP plugin, some are able to access, others are getting this error:

Sorry. Login aborted due to an API error. - Patreon returned: invalidgrant

I’ve verified the connection details. Even reinstalled the plugin. Nothing changes.

If you have any caching setups at your WP site (plugins etc) try turning them off. Also ask your host what kind of caching they have, especially if they are caching requests, calls, cookies.