Hi,
I see what you mean. I'm indeed able to reproduce the issue on your website.
However, there are no errors or strange thing as far as I can see.
It's just that the paypal onboarding popup doesn't callback the plugin's function to process the onboarding on the server side to automatically fill in the fields for you.
I'm afraid we'll have to contact the PayPal technical engineer we know there to check with them what they can find.
It might take a while...
In the mean time, a simple solution would be to add:
if(!hikashop_isClient('administrator')) {
unset($this->pluginConfig['connect']); return;
}
after the line:
parent::onPaymentConfiguration($element);
in the file plugins/hikashoppayment/paypalcheckout/paypalcheckout.php
That will remove the connect button and vendors will have to manually enter their credentials.