Tvheadend

I'm in the UK where a number of Freeview channels (particularly those related to Channel 5) sometimes prefix the titles of programmes with "New: ". It seems that the first showing of the programme uses the prefix and repeats then drop it.

To give me the most flexibility, I use autorec rules which allows will pick up either version e.g.:

^(New: )?Empire$

However, the problem I'm running into is that I'm picking up duplicates where the repeat (which lacks the prefix) is being scheduled. The autorec duplicate handling is set to "All: Record if different subtitle".

The subtitle of the last recorded one is:

US musical drama series. Lucious and Cookie prepare Treasure for the big time. Giselle is furious to be denied the top job at Empire. (S5 Ep 2)[S]

US musical drama series. Lucious and Cookie prepare Treasure for the big time. Giselle is furious to be denied the top job at Empire. (S5 Ep 2)[S]

These are the same so I would expect the rule to realise this is a duplicate and skip it but it doesn't.

Does anyone have any idea what am I doing wrong?

System setup:
Tvheadend version: HTS Tvheadend 4.2.2-36~g60e4409
OS: Xubuntu 16.04
Tuners: TBS 6280 (Dual DVB-T2)

Thanks