Also notable is that CBS Reality is on 2E/11426V (UK Beam) whereas CBS Reality+1 is on 2G/11264H (European Beam).
As you are in the UK, this may have no consequence at all, but the two muxes are on different sats, the transponders have different footprints, and different polarisations.
Here's a couple of questions that will shed light on your situations:
1) can you get any of the other 11426V mux (Food Network UK, Bloomberg TV - see lyngsat.com)?
2) can you get any of the high H channels (CBS action UK)?
3) do you get any of the other 2E low H channels (Film4 etc?)
4) do you get any of the other 2E low vertical channels (E4, E4+1)?
Your dish may be slightly out of alignment, allowing reception of 2G but not 2E
Your LNB may be broken, working only on horisontals, not verticals.
Or something else...