Paypal-Express without forced paypal-account creation (German Seller, German Buyer)

I want to let the customer decide, if he wants to create a Paypal-Account together with his external payment (credit-card..), so he is normally not! forced to create a Paypal-Account (sometimes he may be forced, but i want to make it as optional as possible for german country).

I have a German Seller-Account (DE) with "PayPal Account Optional" set to "ON". The Account is "Verified" and has a "Confired Email-Address" and Negative-Testing is set to "off".
I sent "SOLUTIONTYPE=Sole" in SetExpressCheckout.
I sent "LANDINGPAGE=Billing" in SetExpressCheckout
I sent "USERSELECETEDFUNDINGSO‌URCE=CreditCard" in SetExpressCheckout
I sent a german address together with "SHIPTOCOUNTRYCODE=DE" in SetExpressCheckout
I clean the Cookies between testing.
I use the latest API-version (204.0).

Still in the Paypal-Sandbox-Environment the Customer always! is forced to create a paypal-account together with his external payment (credit card...).

Only when i sent "LOCALECODE=US" instead of "german address and SHIPTOCOUNTRYCODE=DE" in SetExpressCheckout it works as expected, but then the customer needs to manually select Germany in the Combobox.

How can i implement Paypal-Express for German-Seller + German-Buyer without forced account-creation in Germany and test this in Sandbox-Environment correctly?

Thanks for any support that may help!

Solution

As far as I know a buyer is allowed to checkout as 'Guest' so is not initially forced to create a PayPal account.

But (I think) if that same buyer/email address uses paypal to checkout more than once or twice times as guest then he is forced (encouraged aggressively) to create a paypal account.

Now I don't know if that's one or two times in a specific period or if it's one or two times ever. or if paypal have changed that policy and will create an account automatically for the guest anyway.