I noticed the same problem - I'm also using Plex. Definitely the latest version of PMS.
I looked into this just before Daniel replied, but thought I'd go ahead and report my findings anyway
Plex is showing all episodes of this show as "S0 E1" which is a bit weird.
The IceTV XMLTV file labels all episodes as <episode-num system="thetvdb.com">series/371180</episode-num>
I'm not sure if Plex recognises those types of episodes. And even if it did, they're all labelled the same.
Could IceTV maybe add a <episode-num system="SxxExx"> tag for these shows as well?
Failing that, I have a suggestion for DeFenn.
Episode 2 is screening again on 9Go at 7:30pm on Wed (at least in Sydney - I don't know where you are).
With the current episode numbering, this would again refuse to record.
But if you rename the existing episode from your Plex library, and Scan Library Files, then the new episode should record. Do the same with the Wed episode, so that episode 3 can record next Sunday night. Then rename them all correctly after that!
Or you could just watch and delete them before the next episode screens - but you might be like me and record far more stuff that you have time to watch! :-)