Not saving appoiments in Calendar

Question

Hi all,

I have been having this issue for weeks, at times Outlook's Calendar will not save appointments, the issue seems to happen when I close outlook (and I have a appointment window open when I close Outlook), yet when the pop-up and asks if I want to save it I always say "Yes", here is a example one is a hard copy I had printed out and was closing outlook right after and what the same appointment looks like right after.