Check the valuation method of the Item for which you are uploading variants. The item in ERPNext maybe have different valuation method as compared to what you have in your CSV upload template.
Dear Pawan, thanks for the reply.
the valuation method is the default one (FIFO) and I haven´t changed anywhere.
I haven´t touched the template, but now seems like stuck…cannot do anything.
I also tried to delete all the new entries, but nothing is changed…