Heartrate alert during training don't work.

Did you set up the HR alert in the settings of the respective Activity? It works fine for me, on Instinct.

No I set it during the activity/training  at the watch. I don't want a heartrate range how it offers in the training options only a max heartrate and i would change it fast during the training. During a activity it works fine only during training not.

If your training is for example a for running, then you are starting a Running activity when starting the training. Press the GPS button » scroll to Run » long-press Menu » enter Run Settings » Alerts » Heart Rate » set High Alert to the desired value » set Low Alert to off. That should work in training as well, assuming you start the training from the Run activity.

However, I do not exclude that some trainings based on HR override the HR alert setting by its own alerts - I never tested such training. In such case there is little you can do about, aside from chosing a different traininig.

Wow, thanks for the information! I never bothered with the Alerts function as I assumed it was simply the on/off function for alerts from the smartphone. There are so many interesting alerts I would have never seen otherwise

Yes exactly how you write it, I do it.

In the (run) training I set no heartrate, so it could be how you said and only the heartrate in the training will accepted, also I set some during the activity.