Hello, we have some FMB920s on a 2 wire config, no ignition. They have been ok but some have stopped reporting, when we visit they have no LED and movement will no wake them. Need to power down and reboot device. Movement source is set to accelerometer with start delay at 2 sec. But I have just noticed ignition source hasn't been set to accelerometer...would this be why they are locking up? Could anyone advise best settings for 2 wire fitment, there is no ign available. FW is 03.25.18 Rev 08 - Thank you.