wrong refund prices

Hello all,

I have a problem that the prices are rounded with wrong.
I have included the VAT in the price that is displayed. And the prices are displayed with 2 decimal places too. This is all fine as far as it goes.

But when I initiate a return, then it happens that 1 – 3 cents a difference arises. The calculation is of course not correct – no matter in favor of the seller or the buyer.

I cannot deposit the value added tax with 19%.
Each time it is displayed as follows: 19.0000 Probably the error leads here?
Also if I set the price to 4 decimal, they are also displayed on the front page and this should not happen.

How can I work around this problem?