Wrong iPhone receiving all texts!!!!

Within our family we have 2 x iPhones, 1 x iPad & 2 x iMac sharing the same Apple account.

We do this as it's the only way that we can keep calendars, address books etc synced across all devices.

I just got around to updating one of the iPhones (phone B) & now it is receiving all of the text messages for the other iPhone (phone A).

So to explain;

- Someone directly texts phone A. Phone B receives the text, phone A does not.

- If phone B tries to send a text to phone A it is received back on phone B.

Really, really useful stuff Apple. Thanks.

What stupid setting has been switched on by default on the recently updated iPhone & how do I turn it off???

Honestly Apple all this stuff is really cool & funky & seamless but will you stop it all being switched on by default & then being so hard to work out & to turn off!!!!!

I totally get that Apple wants us to adopt the continuity & hand-off thing but for those of us that don't like it it's forced adoption is seriously annoying & turning it on by default is a great way to really annoy customers.