Hello @Tom0369
Thank you for reaching out on the community and telling us about your issue. I do apologize in the issue you're having. That is odd I'm wondering where exactly the issue is. I believe in this case it might help trying to see on a test file if we have a similar issue. This will give us a better idea of where exactly the issue is.
You can do so by going across the top of Quicken File > New > start from scratch > default categories > don't sync to mobile and web. Add your card again and see if you get the duplicate transaction again.
Once you get the chance let us know what you're able to find out. From there we'll see what we're able to do next.
Thanks,
Quicken Francisco