Brought vehicle into Dealer for Service due to Check Engine Light being on and Notification of a Malfunction of the I-Stop System. Service Tech indicates that this is a known issue with the Hybrid Battery in these vehicles that could cause the vehicle to unexpectedly stall. This safety issue is significant enough that they would not let us take our car home while we wait for them to obtain a battery, which are currently on backorder. Pursuant to a conversation with a Mazda Customer Experience Representative this has been a known issue since at least January. We have not received any correspondence from Mazda regarding this issue. It would appear that a Bulletin or Recall is warranted for what appears to be a prevalent issue with significant safety impacts.