Connecting heart rate monitor

Hi all I apologise if this has been asked before but can’t seem to find an answer. My Garmin HRM (ANT+) connects to zwift but more often than not i get the message no signal zwift app is on Windows 10 pc with ant+ dongle and companion app on android phone. Anyone any ideas many thanks in advance😊 Oh if I connect to zwift on the phone I get a full connection every time???