Adding events on calendar it changes date and time

Hi, I’ve had this problem for a really long time. I have the same problem both on my iPad and on my iPhone. When I create a new event, I press and hold on the date that I want to add the event. When the window opens, I then select the time that I want the event to be at and fill everything out. Usually after I click done it disappears and I have to search my calendar and find it. It will have changed the date to some random date. Sometimes it also changes the time. For example, I just pressed and held on November 5. I selected 1:45 PM and filled everything out. I clicked done. It added the event on November 1 and it changed the time to 3 PM. I have googled, and I can’t find the answer. I’ve had this problem through multiple iOS. Yes everything is up-to-date. Yes, my time zone is correct. I’m at a loss. It doesn’t happen every single time, but it happens a lot.