Every time I setup a series recording, I set it up for "Any day, anytime", "First run only" and "SAVE: All episodes until space is needed".
There is an annoying bug where series recordings get changed on their own. The time will reset to the original time of the recording such as 5PM for example, the SHOW TYPE gets changed to "First run & rerun" and the SAVE to "1 latest recording".
These changes happen every time a season ends and there are no more shows scheduled, but it also just happens randomly since a show just now recorded a rerun episode even though there are more first run episodes coming up.
I know these settings are saved on a server somewhere, but there's no reason for you to be changing it at all.
I'd be happy to talk to a developer if you want more information.