Hikashop Paypal Checkout payment plugin stopped working after update to joomla 4

-- url of the page with the problem -- : kiteoutlet.eu
-- HikaShop version -- : 5.0.2
-- Joomla version -- : 4.4.1
-- PHP version -- : 8.1

A few weeks ago I installed the new Hikashop Paypal Checkout payment plugin and it was working fine. However, I have just (finally) updated to Joomla 4 and it stopped working.

When I place an order, I can go through all the steps of the checkout process, and I end up at the screen where I can select my payment method through Paypal. (See attached screenshot.) When I do however, a Paypal logo flashes across the screen briefly, but nothing else happens. I never get redirected to the Paypal page as I did previously.

In the payment plugin settings I can see that it is still succesfully connected to the paypal account.
I already found some posts on this forum describing similar issues ( www.hikashop.com/forum/payment-methods/9...checkout.html#356942 ) that were fixed by adjusting a setting in the "Cross-Origin-Opener-Policy" option to "same-origin-allow-popups". I did this and cleared my cache, but the issue is still there.
I also checked my views and there are no overrides for the new Joomla 4 templates. I have tried with both the default Cassiopea and a custom template and both give the same results.
With error reporting set to maximum and debugging set tor true I get no error messages that can help me any further.

Can you please help me fix this issue, so that customers can pay with Paypal again?

Hi Nicolas,

Thank you for your quick reply. I have done some more testing and I think I may have figured out what is causing this issue. Is there perhaps a minimum amount for an order before it can be accepted by PayPal?

I was testing the checkout process with a very cheap test item and adding 100% discount on shipping using a coupon code. (I have set a 4% markup on the paypal payment method and this was equating to 0 cents for my test order.) When I try to place a test order like this I get the issue of not being able to proceed to paypal. However when I place a more expensive item in my cart and go through the checkout process, I do get to log in to paypal at checkout.

If you still want to check it out by logging in, I have sent you the login details in a private message.