I've been having the same issue withy Venu 3S, same with my wife. Spent two days with Garmin tech support but they haven't been any help yet, I'll try again tomorrow. I have a video demonstrating the problem and they were supposed to send me an email where to upload it today but 6 hours later and still no email. So frustrating.
I had that issue in the past when paired together with 1040 solar,after chatting with support a reset was suggested, with instruction on how to backup, and it was solved support.garmin.com/.../
Same - I have 19.18 installed and I see it drop off after a few minutes. I'm using a bluetooth sniffer and it's clear as day. It works fine and then poof... stops. If I go back to the watch, it claims it's still broadcasting. If I stop it, and re-start it, I see it re-appear... but then drops off again. Not sure why Garmin can't fix this problem properly.
Same with my Forerunner 965 sending heartrate to my wahoo. Soft reset as well as full reset doesn‘t change this behaviour following the Support advise. Need to contact Garmin again.
