After update to 23.1.2, NetData CPU usage jump to ~200% as shown in top. Opnsense is running in a Hyper-V VM. The host overall CPU usage jumped from ~12% to persistently over 50%. After uninstalling NetData, CPU usage was back to normal.
This is the error message when NetData was running on 23.1.2: "apps.plugin pid 1433 netdata states parent 1, but the later does not exist." The error message appeared persistently.