Reduced heart rate readings during activities

Couldn´t agree more. When an activity is started I´ve found the HR sensor to be much more accurate than I expected Unfortunately I doubt Garmin is working on fixing it, it really does seem like they don´t feel this is even an issue sadly. I initially found that baffling but somehow that seems to be their take on it. 

The fixed FTP is another strange one since it pretty much eliminates any chance of me ever using the garmin connect as anything but a gateway to send the data I like to other services (strava, google health connect). I guess Garmin´s idea is that I should buy a garmin power meter, bicycle computer and "smart scale" so that I can properly use the garmin connect for actual useful logging of fitness and training. But the end result is that they just more or less eliminate their software platform as a legitimate option instead more or less forcing me to go for other options while also making sure to stay away from Garmin hardware as much as possible in the future...

I bought the Venu 3 specifically because of the new heart rate sensor and because my Venu 2 wasn't recording my heart rate for an entire workout or bicycle or any activity.. it turns out the Venu 3 is worse.. I now to bike rides and it wont even start recording my heart rate until sometimes the last lap and then its only the last few seconds.. it is the worse experience I have had with any heart rate monitor.. I try starting it again I try wiping the sensor I have tried doing this multiple times while biking but nothing works.. an absolute waste of money considering it is my heart rate I like to keep an eye on.

I dont have a venu 3 but a Forerunner 265s and I have the same issue except for me its the different way around! When I dont track mg activity my hr seems accurate, but when I track my activity my HR rate drops to around 80 and stays there. Even though my HR was 145 before I started tracking. I know that wrist monitors arent as accurate as a chest strap, but this is insane. I personally dont want to workout with a chest strap everytime. As a woman this is also just less comfortable with your sport bra being in the way

I have noticed the exact same thing. I am new to the Venu 3 and have only had it for a couple of days. Yesterday, I was doing a workout on Zwift. My Wahoo reports the HR to Zwift, so the Venu 3 is not involved. However, I was riding at roughly 140 BPM, so I checked the HR on the Venu 3. It showed me 80-something. It never went over 100 BPM, even though I was doing a very hard ride at some point. Wahoo was showing 150, Venu 98. This is just BS. What I did then was reboot the Venu, and after that, it picked up the HR correctly and was within 1-2 beats.

That said, this really gives me a weird feeling because I am wearing the Venu 24/7 to monitor my health, and HR is one of the most important parts. So if it cannot do this, it’s worthless.

Now that said, I used to use Garmin all the time but moved away from them roughly 10 years ago because they always had issues with the different devices I owned. They were never able to fix anything but rather just released a new version the following year, leaving the old trash behind. Seems like they have not changed.

Sadly this is more or less by design. Unless you start an activity on the watch the HR monitor is  waaaaay off unfortunately, often showing HR in the range of 90-110 when it´s actually 160ish. Garmin have confirmed that they somehow do not consider this to be a bug, or even a flaw it seems.

For me, the HR is inaccurate when I start tracking an activity without a chest strap.

So I have done a few tests, and I seriously question this device being a health device. How can it give you feedback if HR is not captured correctly?

Let’s get back to my example. I ride on Zwift and use Wahoo to monitor my HR, so I am all covered there. I leave my Garmin on my wrist because it should be my health device that I wear 24/7. Now, that said, good luck with that because if you don't specifically start a workout when working out, Garmin HR is not capable of showing the correct HR. This is just a mystery to me. If it just updates your HR every 10 seconds when in normal watch mode, I am fine with that, but I would expect it to show me an HR in the ballpark of my workout HR, but it hardly ever does. To me, it seems laggy and very unresponsive.

This device is claimed to monitor your HR 24/7, so how can it be that it does not update correctly when in watch mode? There should be no difference; it should be accurate, but it is not, and let me get this straight, it’s nowhere close to being so.

Today, I was working out at 150 BPM; Garmin showed me 50-60. This is just so frustrating. You could debate that after my workout on Zwift, it’s uploaded to Garmin, and Garmin then takes that into consideration to determine my stress, body battery, and so on, but is this really the case? Secondly, having such a big discrepancy makes me doubt the overall accuracy and data delivered by Garmin.

I will use it a bit more, but at the moment, I am already looking for another device, because I honestly don't trust the data and I am not expecting anything from Garmin. The past has shown me that they will not deliver.

Now, that said: I do feel that if you are wearing the device just in a normal daily routine, with no workouts, etc., the HR seems to be fine, but if you start a workout and don't start a workout on Garmin, it’s ludicrous, and this is a big problem to me

Sorry about that. For me as long as I do actually start a workout the HR reports almost identical data to my HR strap so really accurate.