There seem to be some issues with OAuth, and the developer says it's not worth his time trying to fix it:
no - it’s not a priority. The problems are complicated, and aren’t consistent. With many of the issues, there’s really nothing I can do. Given the lack of interest in any kind of financial support for the plugin, I have little motivation to continue development at any pace faster than what is convenient for me. It’s not that I expect donations in order to do anything; but I can not place work on this plugin above my commitments to my clients.