Metrics does not send information of all LXC/VM

I have InfluxDB and Grafana running and pointed to them in the metrics settings.

Approximately 10-20 % of my LXCs/VMs are missing in Grafana/InfluxDB.

What I did to solve the problem:
- Upgraded from PVE7 to 8.1
- Installed new Grafana and InfluxDB
- Upgraded to InfluxDB 2 (what a pain in the ass)
- installed new LXCs/VMs
- Installed a new server

Everytime the same problem: Some of the LXCs/VMs are missing!

What is the problem?