There have been a number of claims about battery issues with the DJI Mini 2. Specifically, that the DJI Mini 2 has a battery discharge problem, potentially causing long-term harm to the health of batteries when stored in the drone or charging hub.
It’s not so much a safety issue, but one of cost. With shortened lifespan, you’d be buying them more often. DJI has officially responded to the claims now, acknowledging the issue and that they’re working on a firmware update to solve the problem.