PSA: Look at the heart rate sensor of your fenix 5. Has it cracks like mine? If yes, it's a common problem. Send it to Garmin and get a free replacement. Do
Garmin fēnix® 6 Pro Solar | Multisport Solar Watch
Amazon.com: Garmin 010-02157-10 fenix 6X Sapphire, Premium Multisport GPS Watch, features Mapping, Music, Grade-Adjusted Pace Guidance and Pulse Ox Sensors, Dark Gray with Black Band : Electronics
Amazon.com: Garmin fenix 6 Pro Solar, Multisport GPS Watch with Solar Charging Capabilities, Advanced Training Features and Data, Mineral Blue with White Band : Electronics
Garmin Fenix 3 HR, now with an optical pulse sensor