Cannot connect HRM Tri / HRM Run

I didn't use music from watch

have the same issue with my Fenix 6 Pro in HKG, I don't get running Dynamics from my HRM Run and or HRM TRI, contacted Garmin told me to hard reset the watch but with no success. 

Just got my APAC Fenix 6 Pro solar.

Would not connect to my HRM-TRI.

Tried everything. Eventually left battery out for 30 mins. Replaced battery,  tried a few more times and eventually it connected.

But not again... 

Incredibly frustrating!

Update to this.

I contacted Garmin support via email to get a ticket raised.

They firstly suggested it could be interference from my Fore Runner 935.

I replied that I have not had it for 3 months, so no chance of interference, also mentioned I was able to pair it with friends Forerunner 735 XT.

They replied back, and are sending me a new HRM-TRI. 

Will be interesting to see how this goes, considering my current one paris with other Garmin's, I hope the new one works, would hate to think its the watch that is at fault.

Will update once I receive the new HRM-Tri

Have you tried putting the battery in reversed for a few seconds before putting it back the right way? That's often fixed connection issues.

The battery in my HRM-Run recently died. I replaced the battery (just under 3.3v) and my Fenix 6X Pro Solar refuses to see it. The 6X works fine with an old HRM-Run (the sensors on the strap are literally falling apart, but still work) and a Polar H7. I've tried all the steps that Garmin recommends, also called support, they don't really do anything to fix it.

I've restarted the watch 3-4 times, removed/replaced the battery twice, left the battery out for 15 minutes, nothing fixes it.

UPDATE: I put sensor gel on an hour ago, tried to pair the strap several times. nothing. Then as i'm typing this, i tried it again.....and now the 6x sees it, and since i put the strap on, i haven't changed *anything*.

I work with computers for a living, and inconsistency and unreliability is absolutely maddening. The HRM-Run strap is the poster child for unreliability.  If any other strap provided the running dynamics this one does i'd switch in a hot second. 

Never had one issue using the Tri for several years and 4 different Garmin models.  Purchased for me as a gift when I had my 235 in 2016. Used it with my 935, 945 and F6.  I rinse it after every use, wash it once a week, change the battery yearly and it's still going strong after 4 years.  

No idea how well it works, but the new version of the Wahoo Tickr X supports most of the running dynamics and follows the standard.  You can read a review here:

https://www.dcrainmaker.com/2020/05/wahoos-new-2020-tickr-tickr-x-in-depth-review.html

i'm having the same problem, with the fenix 5 it always worked flawless. With the 6 it was perfect untill the last software and the behaviour is quite strange and random:

I can pair it, and it connects easly from settings/sensors

If i start a run it don't see the sensors sometimes untill i force the download of the data at the end of the run, but in this case all the running dynamics is lost.

Sometime it got recognized immediately as it was with the old software.

I'm 100% sure is a software bug i hope it will be sorted soon.

The newest beta's have a different Sensor SW version and the Sensor Hub does mention disconnect problems (mainly with BT) - may be worth trying 9.95 and seeing if it connects better.

I have a Tempe and a HRMRUN and for me the HRM connects fine, but I often need to go into the Sensors menu to speed up Tempe's reconnection