Inconsistent data - CPU and Disk

[brembygit]

Hi,

I noted some incongruencies on CPU and disk info
this is my config

When I run the script as a service, I get the following values

If I run interactively
python3 src/system_sensors.py src/settings.yaml
I get this

I have another Raspberry with an external USB drive

When I run the script as a service, I get the following values

If I run interactively
python3 src/system_sensors.py src/settings.yaml
I get this

I don't really understand the reason of this behavior, I re-installed the system_sensor in both the devices today and I pulled down the latest version from git, but I still see this "flipping" on the data

any ideas?