Assistance in setting up the plug-in correctly

I am using your plug-in and the Polylang plug-in on your website – https://benchk.com/ – I have a very big problem with the correct setting of the plug-in. Why does it happen that on the German site prices are displayed once in PLN and once in Euro? I would like that after selecting the site in DE and EN languages the prices are always displayed in Euro, and in PL language always in PLN (regardless of localization)