How do I stop Calendar from "helping" me?

Since the latest update, the Calendar has been vexing me a LOT.

First, it no longer separates edited recurring events from their initial string. Formerly, if I had to change one event of a weekly event, it would change that one and forever separate it from the other recurrences. Now, it keeps that edited event in the same string, and has even changed all of them even when I click "change just this one event".

Second, say I have an event at 3:00pm "Dr appt 3:00", but have to leave at 2:15pm and mark it in my calendar as a 2:15pm-4:00pm event, when I type in "Dr appt 3:00", the Calendar will change it to a 3-4:00pm event. It didn't use to do this, and I really need it to stop, or I need to learn the magic words to make this not happen. This "feature" has changed some of my older events from before the iOS update, which makes it impossible now to have an accurate calendar history.

How do I fix these things?

Thanks!