A manual recording will always override a series link, and that's what you seem to have done here.
Once that manual recording of a particular episode has been set, then the SL will fall in-line with that and TiVo-software doesn't allow an override.
The only way to lose that planned recording is to manually cancel it, in which case TiVo-scheduling logic is effectively told to not record that episode.
Quite happy to look at any other specific examples that you can provide.
I'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media. Learn more
Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks