I have seen this problem mentioned before but it has still not been addressed as far as I know. If I put series record for a show it not only records the show but then records it again later in the week when it is repeated.
The only time this has happened to me is if the recording does not finish correctly,
and it therefore finds a repeat to replace the incomplete one.
If, for example, the recording is deleted before it has actually finished recording
or some fault has stopped it record for the full time.
I am suspicious that I have the opposite problem. I've got a few series that I've set for recording in the past that only ever recorded 1 or 2 episodes.
With out the luxury of 's1/ep2 of5' type info. the only way to figure it out is by going onto Wikipedia or researching on the internet. I can not tell if or know why they have all been recorded.
Sometime the next episode does not appear in the scheduled recording list, although it is marked for recording if you look in the guide. Then if you hit record on it twice to re-add it, it appears in the list.
Just to emphasise that this is always a broadcaster problem rather than BT or Youview and you need to take it up with them.