No performance data in Influxdb

Icinga’s logfile will tell you.There you should find sometime like:

[2020-07-10 06:30:32 +0200] information/WorkQueue: #5 (InfluxdbWriter, influxdb) items: 1, rate: 1.38333/s (83/min 426/5min 1280/15min);

or an error message.