Hikvision AcuSense NVR

Hello all,

I have the Hikvision AcuSense NVR DS-7608nxi-k2.

Now I understood that I can also connect non-hikvision cameras, and that the NVR would then take care of the person detection. Now this only works for 2 cameras and when I want to add a third prosonic detection it says "camera insufficient resources for analysis program people" (google translate). Does anyone know a solution? otherwise this NVR will have to be returned.

thank you very much in advance