Heart rate and step counts doesn't work on 21.19

i've been having issues since 27 November 2024, i tried everything, you name it, like everything, and couldn't find a solution, i'm out of warranty so what else i can do? is there a way to downgrade firmware to 17 or 18? anyone, please help.

I have the same issues, following an update to the beta 21.18 firmware. The full release 21.19 did not correct the issue. I've tried rolling back to previous FW versions, then updating back to the latest, and a few in between, just hoping that something reinstalls and fixes the watch. No luck so far. 

Only way to get it back is a soft reset - hold the LIGHT button until the watch turns off, and back on again. It will work for a seemingly random period of time, between 2 and 16 hours, before it fails again. 

SNS_ERR.txt in the GARMIN folder shows the Sensor Hub failing?

12/07/24
02:44:19
Sensor Hub probe passed; SWD resetting
Reset loop count: 1
Sensor Hub probe passed; SWD resetting
Reset loop count: 2
Sensor Hub probe passed; SWD resetting
Reset loop count: 3
Sensor Hub probe passed; SWD resetting
Reset loop count: 4
Sensor Hub probe passed; SWD resetting
Reset loop count: 5
Sensor Hub hard resetting
Reset loop count: 6
Sensor Hub hard resetting
Reset loop count: 7
Sensor Hub hard resetting
Reset loop count: 8
Sensor Hub hard resetting
Reset loop count: 9
Sensor Hub hard resetting
Reset loop count: 10
Sensor Hub Reset: Rx Fail, v3109
12/07/24
02:45:00
Sensor Hub probe passed; SWD resetting
Reset loop count: 1
Sensor Hub probe passed; SWD resetting
Reset loop count: 2
Sensor Hub probe passed; SWD resetting
Reset loop count: 3
Sensor Hub probe passed; SWD resetting
Reset loop count: 4
Sensor Hub probe passed; SWD resetting
Reset loop count: 5
Sensor Hub hard resetting
Reset loop count: 6
Sensor Hub hard resetting
Reset loop count: 7
Sensor Hub hard resetting
Reset loop count: 8
Sensor Hub hard resetting
Reset loop count: 9
Sensor Hub hard resetting
Reset loop count: 10
Sensor Hub Reset: Rx Fail, v000

I did the soft reset (hold light button until it's off), and got the HR back randomly but failed after a while like what you have mentioned. But so far, the step counts never works.

How did you roll back the firmware version 20.32 (my last working version)? I rather have a fully working unit with older firmware version than newer firmware but broken functions.

I have the same issues, following an update to the beta 21.19 firmware. It hasn't measured my heart rate and steps for 5 days and the watch doesn't vibration after notifications. I'm desperate.

Did you power off the watch? waited one minute and then powered it on again?

Yes, I tried to reset the watch by turning it off and on again several times, but to no avail.

I saw this , maybe worth a try

forums.garmin.com/.../reinstall-software-for-forerunner-965

Just to be sure , soft reset, When you turn off , you need to hold in light until it switches off , not use the power off option on the control wheel

I tried reinstalling as you recommended. It currently shows fw 21.19*. However, the sensors still don't work.
I reset by holding the light button until the device turned off, after a few minutes I turned the device back on via the light button.

I still have the same problem. I have version 21.19, but none of the sensors or device vibration are working. Sensor hub reports fw 0.0.1, WHR: 0.00.00 and BMX: 0.0.0(!). I have the same output as you in the SNS_ERR.txt file. Did you manage to solve the problem?