How high will the early repayment penalty be?

Can someone please explain to me again why one should not pay a prepayment penalty? Because interest rates are currently so high? I don't quite understand... But of course, I would be very happy!

Gladly.
The bank gets the money back from you at time X.
At that time, the bank reinvests the money for the same term (simplified) as the remaining term of your loan (in reality, the exact cash flows are replicated, prepayment options are considered exercised, and calculations are made until the cancellation option according to §489 of the German Civil Code – so with a fixed interest rate of 30 years, not for e.g. still 25 years. But details go too far here.)
Then a comparison is made – what the bank earns from the loan and what it earns from the reinvestment in securities (mainly mortgage bonds). If the reinvestment interest rate is higher, nothing is charged and vice versa.

That was the simplified explanation.

Thank you very much for the nice answer!!! That means with our interest rate of 1.89% we should very likely be able to get out of the contract without a prepayment penalty if we sell the property? That would of course be a relief. We had expected at least 20k.

Good new start!

The feedback has been clearly positive. After all, nothing prevents the bank from charging the clause for the prepayment penalty even if the bank has not suffered any damage, unless the prepayment penalty directly refers in the contract to an interest loss that does not occur in the current interest rate environment with a new investment.

Thank you for the kind encouragement!!!

Still, I wouldn’t understand the bank; they could first demand a reasonable compensation from me and then “reinvest” the money at better conditions, or am I missing something?