When will I get billed for Argo?

Hi,

Domain created & billed on 23rd of the month, Argo added on the 26th Sept.

The initial $4.50 pro-rata Argo upgrade was billed on the 26th Sept and I’d expected the bill on 23rd Oct to include the month’s Argo usage (around 100GB) but have only been billed for the basic plan + $5 Argo monthly fee.

Is this a bug or am I mis-reading how the Argo billing works per the below support doc?

Argo is also usage-based, so each invoice reflects the prior month’s usage. For example, your September invoice will include charges for Argo usage in August.

https://support.cloudflare.com/hc/en-us/articles/115000224192

Thanks