I have used the HRM-Dual for 2 years without any problems. I used it with a Concept2 rowing ergometer, with a Tacx bike roller and directly with the Strava app on my smartphone when cycling. Never the slightest problem. Then I bought a Garmin Vivoactive 4 watch and connected the HRM to it. Unfortunately. After a few days, the connection to Strava suddenly stopped working. Then the connection to Tacx stopped working. Only the pairing to the Concept2 works flawlessly at all times, although this is the only device that does not belong to the Garmin empire. I have now spent hours trying to re-establish the pairing with Tacx and Strava. With Tacx it now usually works again, but always with a lot of effort and a lot of lost time. I have already reset the HRM 20 times (insert the battery upside down and wait 30 seconds) and tried everything possible. My suspicion: Garmin is somehow trying to prevent the HRM from being used without a Garmin watch in order to sell more watches. Has anyone had similar experiences?