Hi Manu, looking what you have already pasted I can affirm this condition does the prorating calculation maybe by weight. Note the first item represents something around 30% of the weight, while the other one 70%. So you'll have in the header the full price condition. So it's make some sense.
However, to provide you a solid response, I would suggest you to use t-code V/06 and locate the condition 'ZVER'. Check the 'Scales' section, see if there's a formula assigned to 'Scale Formula' field and paste the text code here
Thanks