Hello @John Wendt
Thank you for reaching out on the community and telling us about your issue. I was taking a look to see if I was able to enter a check pay from the Calendar and noticed I could enter it from the main Calendar screen but not clicking on the specific day as it won't let us add a bill reminder. I'll leave a photo down below showing where this is. If you could double check this as well to see if you're able to add check pay transactions from this area let me know.
Thanks,
Quicken Francisco