MSGraph Mail Poller Erroring

Hello,

We've been using the MSGraph Mail Poller plugin, which has been running frequently with no issues for a few months now. Over the last couple of weeks, it's been intermittently erroring once a day, this process is ran every 10 minutes. 

The node is returning true for errorOccurred but the errorMessage is always either null of 'Error executing this request' with no other information. The node itself is not erroring so the process from an Appian perspective is running as expected. 

We've haven't found any errors in the logs or from the mailbox side when it's being polled. 

Does anyone have any information on what could be triggering the plugin to error, or any thoughts on a way to find more information? 

Thanks!