After working fine for many months, it suddenly stopped working mid-training. I figured it was out of battery, so I replaced the battery - and it worked for maybe 5 minutes and then dropped out again. I was unable to connect it again. I took it apart, replaced the battery (unsure if I might have put in an old battery). Still same issue. Also the HRM cannot know, when you stopped your activity, it simply ā€žstupidā€œ records HR and steps. What works on supported watches (Fenix 6 should be among it): Start an activity with HRM Pro connected, leave the watch behind, do your workout, come back and stop the activity on the watch. I've had the watch for less than a week, and it worked perfectly for a few days then a whole load of functions just stopped working. Heart rate monitor, step counter, compass: all just completely unresponsive. I've made sure the software is up-to-date, done soft resets and a full master reset. Two days ago, I went for a 5K run with my HRM-Pro synced to my Phoenix 6. I always wet at least the strap's pads with water or saliva, check to ensure it is connected to the watch, and then when I know everything's connected, I go for a run. I was doing zone 2 HR training (141 to 156 BPM for me) and things seemed to work fine. If you have problems pairing the heart rate chest strap with your watch, or the monitoring performance degrades, you can reset the heart rate chest strap or replace its battery. Make sure there are no other heart rate monitor chest straps in the surrounding area that are interfering with your product. The battery in the heart rate chest strap Find helpful customer reviews and review ratings for Garmin 010-12955-00 HRM-PRO, Premium Heart Rate Strap, Real-Time Heart Rate Data and Running Dynamics at Amazon.com. Read honest and unbiased product reviews from our users. After reading through this thread I tried connecting my HRM pro to my wifeā€™s iPad and it worked fine. Iā€™ve been using my HRM pro on my iPhone for months and it suddenly doesnā€™t work. Whatā€™s going on? It was working fine yesterday. *The problem may actually be beyond Zwift because I cant even connect the HRM Pro to my iPhone in Garmin Hi, Iā€™ve been having a pretty tough time getting HR data on Zwift. Iā€™m using a Garmin HRM-Dual that came with a Garmin Edge 520 Plus Bundle. Iā€™m hoping someone can help because Zwift CS keeps reiterating the same troubleshooting steps. Hereā€™s what Iā€™ve done so far: (1) Verified the original issue was the battery was dead. Took out old battery, let module discharge (15min), put in new August 31, 2010 at 7:21 pm. My Garmin 305ā€™s heart rate monitor is on the blink. It was working off and on and now is not reading at all. I have tried bending the gold contacts, cleaning contacts, vaseline on contacts, new battery, soft reset, turned strap around backwards and still no go. Just HR: any well rated strap garmin or not will work. Probably garmin dual or polar h9/h10/oh1 are good options. Running dynamics (within garmin ecosystem/app): HRM TRI or RUN. Honestly with a garmin watch on the wrist this is giving most people the top end of functionality they will actually use. All bells and whistles: PRO SDHzkr.