Villa Park has been anything but a fortress since Lambert took charge of the club at the start of last season.
Lambert has orchestrated just five home victories from 21 Premier League games, notably chalking up nine defeats in the last 13 stretching back towards the end of December.
The run includes defeats to Liverpool and Newcastle already in front of the Villa supporters, while the club were unceremoniously dumped out of the Capital One Cup by visiting Tottenham in midweek, who are the next visitors on October 20 after City.
Lambert said: "You need to win your home games.
"You should have a good solid base at home, but we seem to be doing it the other way around at the moment, winning away from home, and finding it hard at home. I don't know why that is. It's strange.
"It's not as if we set our stall out any differently. We always go out to try and win every game we play in, and I'll never change that
"We've too many fans who come to watch us, so we can't sit back.
"Sometimes we are forced to because visiting teams get on top of you, but we never deliberately set out to defend.
"We know it's something we have to put right, to improve, and I'm sure it will come. The law of averages says it will come."
One of the keys for such an improvement will be goalkeeper Brad Guzan who produced a superb display in last Saturday's 1-0 win at Norwich, in particular saving a penalty from Robert Snodgrass.
Crucially for Villa it was their first clean sheet in 26 league games, stretching back to a goalless draw at Stoke on December 8.
"Against Norwich his handling was brilliant, he won everything," said Lambert.
"When you've a goalkeeper like that, who you know is going to come and collect the ball, it's certainly a great thing to have.
"There are obviously some great goalkeepers out there, but I can only speak for Brad and what I see every day, what he has been like in training and in matches.
"He has been absolutely brilliant for us, and apart from that, he is an absolutely top guy."