Found this configuration to work in the end, by swapping black wire from L2 to L1, so that both switches worked the same way.
Thanks for your help with this.
Thanks for your reply.
I have attached another diagram in my album of how the wires may look after changing to the new switch. Could you check if this is correct, as I don't understand all the C and L1, L2 terms.
I have just purchased a double light switch for my hall/bathroom lights. Not sure if it is the right one, as I know nothing about electrics. I could not get the same type as my old switch unit but I have attached a diagram of the old switch and a picture of the new switch. The Left hand switch...