I have no idea, but you may be correct in that it could be a shared drain pipe, i have yet to take to the store where i purchased and because it's only a month old, I really don't want to open it up (I don't know too much about the internal workings of the machine yet
We are no longer locked down as of today so next week it goes for a check up (only 4kms from my home so no problem to take it)

So I just filled a milk jug with hot water from the hot water tap on the machine and the dripping stopped...