Batterie dies and no USB connection

Hi,  my Instinct which I bought at Decembre 2018 drives me crazy. Since ond day the battery lifes only 4 hours instead 10 days. I thought maybe it is the new firmware (5.50) the reason, but I could not get a connection from PC's via garmin express anymore... is there a possibility to get in UDB mode anyhow else?

Regards

Marcel