Erroneous heart rate zones

Go to your watch settings > user profile >Heart rate and power zones > Hear rate 

Scroll down to reset the zones.

Then switch to another zone system, do a reset

Go back to your preferred zone system (lactate, max or reserver) and reset again.

At this time, you should be back to the default.

This is not the normal procedure, but there is a bug somewhere.

Note that you might have to reset the zones after a new HR Max or Lactate detection. It is unclear why this is needed sometime but not always. We have seen several users complain about a change in zones after HR Max detection, using LTHR zones. 

I am using HRR and I don't have this issue. That said, I have deleted hear rate zones by sport yesterday and I had to do the reset described above...

Thank you very much for the reply, I will try this because it has already happened to me on several occasions and it stays with some default areas. 

I've tried to do the process you explained and do a test activity but it still shows the zones incorrectly after finished. I don't understand these bugs in Garmin that ruin the user experience. 

Any chance you have another Garmin device where the zones are set up differently?

After you have reset the zones on the watch, sync with Garmin Connect. Now, are the zones correct in Garmin Connect?

I currently only have the Epix. In Garmin Connect it shows me the same zones as on the watch based on the lactate threshold data but at the end of the activity reviewing the zones, the Z5 always starts at 163 and my threshold is currently 164. It shows me some default areas and not the lactate ones. 

I think your values are in fact about correct. By default the zone 5 starts at 100%. So this is that 1bpm that bugs you?

Is Zone 5 starting at 100% in zones definition?

No tiene sentido que con estos % mi Z5 comience en 163. Debería comenzar en 172. My HR Max is 185.

There is a bug in Garmin Connect mobile. If you reset the zones, the app will tell you they have been reset, but won't update the screen. You have to go back one level to "hear rate" in the menus and then return to the "zones" in the menus to see the change. I tested this several times changing the zone system, resetting, etc.

It looks like 163bpm, and you might only see a display bug issue. Does this sound right?

After resetting the zones several times and changing the heart rate mode also several times, In today's training it does indicate the range of the zones correctly. I don't know how long this will last. I don't have a lot of confidence in that.