Why does the Instinct 2 record intensity minutes when none have been done ?

My HR max is 196.
Moderate intensity minutes are set for range 4 (80-89%) = 157bpm - 174bpm.

High intensity minutes are set for range 5 ( 90-100%) = 176bpm - 196bpm.

I was at work today, and didn't hit range 4 (for single intensity minutes), or range 5 (for double intensity minutes).

Still, the Instinct 2 says I reached 42 intensity minutes today. 40 moderate and one high (x2). Results in 42.

What is wrong there ?

According to my tactix 7 pro I only reached 9 intensity minutes in the same period. And to note, the tactix is set to HR range 2 (moderate) and range 3 (high). So much more sensitive. The tactix should actually show much higher results than the Instinct 2 in this case.

The HR charts for both watches are consistent. Also to each other.

My conclusion:

The intensity minutes of the Instinct (2) are extremely too high and give fantasy values.

When set for range 4/5, the watch should not have output a single minute of intensity. But there are 42.