
How old are they both ?
Are they left alone or unsupervised for long periods ? Also have you cleaned all the *mess* with cleaning agents that get rid of the smell ? Although we cant smell it they may be able to.
I wouldnt let them have access all over the house if this is what they are doing . I would keep them contained to the room that you are in if that is possible . I would remove the paper from the kitchen and I wouldnt give a treat for going on the paper in the kitchen . This habit needs to be broken as they are seeing this as acceptable . I would start by putting the paper as near to the backdoor as possible and gradualy moving it to outside . After the paper is removed from the house ONLY reward for going outside . I would have a nice tasty treat ( we use the Asda treats ) and praise lots as well when they go outside . It will be harder trying to train two than the one . If you see them about to do their business say "NO" firmly and try to put them outside if possible . If they then go outside then treat and reward as I mentioned before . Do not shout when you find the mess if you havent actually seen them doing it as they wont know why they are being shouted at .
Good luck
Lel