Replaced double light switch...confused!

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Hi, I replaced an old double light switch, one switch does my porch light, the other should do my lounge lights. It was an old switch with L1 L2 and L3. I followed these instructions when changing it :

L1 . . . . COM
L2 . . . . L1
L3 . . . . L2

And it doesn't work. I have posted a photo, any ideas? The porch light works, but that was just two wires

I've just checked at the back of the switch with a multimeter and I'm getting 240 when switched on. But at either of the wires coming out of the wall to the two light fixtures, I'm getting 2v when switched off, and 3v when switched on!! I have no idea what's going on

20210521_101024.jpg
 
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Look at the other switch of the pair of two way switches, the Com wire must be correct, if other two are swapped it just means both switches in same position may not be off, in the main the com wire on the master switch other end will not have any other wire with it, the two change over contracts will have two wires at other end.
 
A common error about which terminal is which occurs when the old switch plate has one switch upside down

up-down switches_2.jpg


Very easy to make this error.
 
Is there another switch that also controls both Lights ? Are they both wall lights ?
Which of the wires yellow,red,blue are measuring 240v at the switch ,when switch is ON ,and which measures 240v when switch is OFF
 
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