Hello & Welcome to Just Answer,
Sorry I didn't see your question earlier and to hear of any issue you are having with your device.
To help you with this issue, may I ask:
1) Was the heart rate monitor IN USE (being worn) at the time you tried to pair the monitor to the device? If not, that is a KEY FACTOR in pairing the monitor.
I also have a link to a "troubleshooting" article for this type of issue. Please click the link below to see that article.
Click Here for Article --> https://support.garmin.com/support/searchSupport/case.faces?caseId=%7B7d0dc6c0-4ffc-11dc-4ec8-000000000000%7D
I hope this helps. Please let me know what you find or if you have any more questions.
Thanks, ***** *****
I see it has been a few days and I haven't seen a response on this page, so I just wanted to follow up to see if you have any more questions concerning this issue OR if the issue was resolved?
I look forward to any further questions or results that you may have.
Thanks, ***** *****--. .-(im)