Does Shopware charge here?

Hello everyone,

For example, I have this calculation here:

 

The positions together result in: 

42.99-3.30-1.93 + 5.95 = 42.61 (so far so good) https://routerlogin.uno/

but how does the shop calculate the 39.83? https://19216801.onl/

If I include the VAT there is 39.822429906542056074766355140187 net and 2.7875700934579439252336448598131 VAT

What kind of rounding is that? https://192168ll.link/

I come to 39.82 net and 2.79 VAT

can someone tell me something about it or did I not understand something commercially?