I have to log this somewhere so others can see the problem and the solution that worked.
I use website builder for my website shop.
I have been using PayPal on my shop for a decade or more. I had a problem over 2 years ago that people would complain about them unable to pay via PayPal on checkout of the basket in my online shop. Initially I couldn't replicate it and then I could for a short period. The ISP blamed the local machines and closed the call after 2 weeks.
This happened on and off for a long time. I have over 400 items in my shop so no idea how many sales I lost.
I logged a call again 2 weeks back and eventually found a useful technician at the ISP who tried numerous things which led me down a direction that solved the problem.
SOLUTION:
So the problem was the titles in shop will support 67 characters including spaces, as soon as you go to 68 the PayPal log in pop up would open and close instantly. But if you go back to 67 character including spaces you can launch the PayPal pop to pay successfully.
The reason I could replicate it sometimes and not other times was I would choose always 1 or 2 specific items to test the popup and other times I wouldn't use the same 1 or 2 and then it worked. Go figure, that took a long time to actually figure out that we were replicate it 100% the same each time.
Then when I found out on one day that I could checkout with item A but it failed on Item B I realised it's the item in the basket that is the problem.
So I ended up stripping a section at a time off the problem item and then trying to pay. 1st it was the shipping, then the photos, then the description and finally I removed the title except for 1 word and then it worked. I added the photos back in and it worked, I added the photos back in and it worked, I added the description ack in and it worked and then when I added the title back in it failed. SO I started to strip 1 character off at a time and tested the payment till I found it working at total characters of 67.
When PayPal brings the info from your site over to them during the login box redirection it must hit the 67/68+ character problem.
I was able to shorten all my items in the shop to 67 or less and now all my items work in checkout.
I hope this help someone else as this was a pain for over 2 years. I ended up having to add other payment methods to try and continue getting payments in.
