You can definitely have possession that is not really doing anything.
Keeping the ball has value because it gives players control and makes the opposition move, but eventually the team has to recognise when an opportunity appears to go through, around or beyond them.
I’d avoid suddenly demanding more forward passes. That can turn safe possession into rushed possession.
Instead, give the players a reference such as: “What has our possession moved or opened?”
In training, use a directional game with target players or end zones so the team still has a reason to progress. Rewarding ten passes can make the problem worse because the players start collecting possession rather than using it.
At U12, I’d be pleased they are comfortable keeping the ball. The next stage is helping them understand that possession is a tool.
The question is not how many passes we make; it is what the passes change.