Questions about Sigma Sport Bc 7.16 Ats

The device often does not connect to the transmitter on the bike and accordingly does not display any speeds. The distance is as required, everything is mounted correctly. Sometimes it works, sometimes it doesn't or it gets stuck. Does anyone know this problem?

Hello.what kind of batteries does the Sigma BC 7.16 ATS need.are they included in the delivery?mfg Television