https://www.kpm-berlin.com/en/manufactory/kpm-history/

Did you read the link ?? KPF and KPM can be the same but KPM by the royal manufactory is a different company !! I know this is confusing but you have to be aware of the company name !! Kister was allowed to use the KPM but is a different company from Koniliche which also used the KPM initials !!