Hi Paul. the best thing I can do is copy the answer that resolved my issue. See below in bold.
When setting up a series link go to Advanced and select which box you want the recording to be made on. It will then be recorded on that box going forward, even if the default recording box is the other one.
So all you need to do is reset your series links to record on the box you want them to.
Unfortunately to reset the links, you'll need to delete and reset.
You can also use the same method to record individual programs rather than series.