PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU COMMAND80468 root 86 0 54M 33M CPU1 1 443:26 100.00% /usr/local/bin/python3 /usr/local/opnsense/scripts/netflow/flowd_aggregate.py (python3.9)
PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU COMMAND15527 root 96 0 30M 20M CPU1 1 14:19 99.55% /usr/local/bin/python3 /usr/local/opnsense/scripts/netflow/flowd_aggregate.py (python3.9)
Now the overall CPU activity is lower, but there is still a lot more going on than before the upgrade.