Seeing the polling queue isn't going to be helpful. It's based on topic and just runs down the list that you see in the AMP Group -> Basic -> SNMP Polling periods. 'Poll now' does not include routers / switches polling as those devices often lock up, refuse polling, or drop/ignore the poll if polled too aggressively.
You're better off looking for errors in:
/var/log/httpd/error_log
/var/log/async_logger_client
If you're not seeing errors there, then there's some additional logging you can enable depending on where the issue could be. If you get to the point where additional logging is necessary, that'd be a good point to open a case with support.