Support notes that units with serial starting "9123A" require a firmware update to fix battery drain. Yours qualifies.
While JVC does not maintain a stolen goods database, you can ask the seller to provide the serial number, then call JVC business support. If the serial was originally sold to a rental house or school district and later "lost," that red flag will appear. jvc serial number search
JVC (now part of the JVCKenwood Group) typically offers a 1-year limited warranty on new electronics. By running a serial number search, you can determine the manufacture date or purchase registration date to see if your device is still covered. Support notes that units with serial starting "9123A"