This is more of an FYI, than anything else. Your website is blocked by mcafee when you try and pay for something as having ■■■■■■/■■■■. I tried to buy something at work, your non secure part is fine, but when you try and pay for something i get blocked.
You’re using a shared SSL certificate so it must be that another site has caused this to happen. Also it may be that the company that your customer is using the internet from has additional filters added to avoid anything that sounds like a ■■■■■■/■■■■ site to be blocked.
The only real solution is to purchase your own SSL certificate.