Why is my email marketing checkout link not working for customers?

[Boundjon]

I get most of my sales from email marketing and in this case use checkout links from shopify (using shopify payment) I have noticed that more and more of my potential customers say that they can not open the link. When the try to open the link they just get the "something went wrong" message. 
This happen both on laptop and on mobile for them and not just one browser or device it is all of them.

The big problem is that I have contacted the support several times and they can not find anything wrong. I have checked SSL Certificate, IP Blocking everything is fine. I have tried access the checkout link from android, iPhone, laptop, the 5 biggest browsers and even from a VPN accessing from different locations, I have even asked friends in different countries to try it and it ALWAYS works. I can not find anything wrong with it. But still, more and more customers starts to say that they can not open the link.

I don't know what to do I have really tried everything and I can not find anything wrong with the checkout link. But when up to 50% of my customers now say they can not open the link this really effects my business and my sales are decreasing fast.

Please help me with what I can do.

[YOD_Solutions]

I have noticed similar issues with "pay invoice" button in emails for other applications. This happens for some email apps, such as, outlook windows app.  The problem is when you click on the button, it does not send the complete url to browsers - it clips some url paths. You can ask your customers to send you the url link that does not open on their browser and see if this is the issue. If this is the problem, you can include the url as a text in the email and inform the customer to copy/paste the url on a browser if the other option is not working.