Shipping Estimate v2.3.1

[Debrun]

I have installed Prestashop v 1.6.1.24

I installed the shipping estimate module. I have added a new carrier and to highlight my issue i have set the banding as 0-15 kg for £5 and maximum weight 15 kg. Add handling cost is NO and no handling cost has been entered on Preferences screen.

 

I add one item to my shopping cart with a weight of 4 kg. The carrier cost offered on my invoice is £885. There appears to be an underlying lump charge of £880 being added to my shipping costs. if i change the shipping band to 0-15 kg for £1 the carrier cost offered on my invoice is £881.

 

Can anyone please advise me where i can find and eliminate this £880. It is not a value i have entered.