ps_order_invoice_tax duplicate entries

[ptityop]

Hello, I am trying to troubleshoot an issue i have with my shop. On the invoice sometimes the shipping value comes out in 2 separate amounts. The total of the 2 amounts are the actual shipping tax value but it comes out splitted in 2 separate amounts in the invoice. I noticed that in the ps_order_invoice_tax DB table I have duplicate entries, this is totally random and I do not know what can be causing this. what happens on the invoice is that the total amount gets divided by 2 and shows as 2 different amounts (i know it is a headache to understand) Also if I take the invoice ID from the database and compare it with the invoice ID in the admin those do not match .... complete mistery ...