I have reported this bug many times and it has never been fixed. I do not have any discount or margin for this manufacturer - this calculator cannot be used normally.
This problem can be seen in the video:
https://piekielko.com/images/cost.mp4
In the video you can see that I did not indicate any category, but I chose the name of the producer "Turkmenistan"
The rule that causes this conflict is the 3rd item on the list - this is a bug, because the rule applies to other manufacturer names than Turkmenistan
The rule calculates a discount of -15% for products with the selected manufacturer but no category selected. The rule works well, but it negatively affects the calculator, which further raises the price instead of lowering it - for products that have nothing to do with this rule
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Virtuemart 4.2.2