Hi,
It seems to me that your new issue is not related to PayPal and that by "automatic discount", you're actually talking about a coupon with the "Auto load in cart if possible" setting turned on. And since HikaShop doesn't handle multiple coupons, when you use the points and that it generates the coupon for the points, the auto loaded coupon is removed from the cart because of that.
I see two potential solutions to that:
1. AWO Coupon is supposed to handle multiple coupons and supports HikaShop. I don't know if that will work fine with the points coupon, but I think it will (you can ask the AWO Coupon developer before trying if you want to make sure).
2. Configuring the HikaShop user points plugin via the Joomla plugins manager and then adding the "user points" view to your "checkout workflow" will allow you to have a separate interface on your checkout to use points or not and they will be added to the order as additional rows, not as a coupon. That way, you'll still be able to keep the auto loaded coupon in the cart.