Why is Apple Pay not showing up in Safari during checkout?

Hello my fellow MacAddicts,

Today I discovered what may or may not be a bug in the Apple Safari on both iOS and OSX systems.

On two different websites I was in the process of purchasing stuff. It was my understanding that both companies accepted ApplePay, but when I went to close the deals there was no ApplePay option available.

After contacting one of the companies, they were having their techs look into it.

But I was determined to find out why this was happening. When I switched to the DuckDuckGo browser there was no problem. After much digging I finally found the culprit. If I was signed into the perspective websites the problem continued. If I signed out and chose the “checkout out as guest” then the ApplePay was offered.

Anyone else had this issue?

Do tell. 🤷🏼

[Re-Titled by Moderator]