On my pi-hole, that pie chart shows the query types as a % and that % matches what’s in the pi-hole API that the app plugin polls from. So I would still have expected the LibreNMS to chart that as 50.00% A and 50.00% AAAA if they match.
You might try checking the output of ./poller.php -h HOSTNAME -r -d -v -m applications (run as your librenms user against the pi-hole). Usually errors for InfluxDB show up as a HTTP 400 error in the output.