Class features, but probably an anatomical problem

So after I Thanks to a very insightful trader two ROX 8 computers and 3 chest straps have been through, I can say one - but essential for me gripe - confirm.
However, the is more justified in my anatomy.

In short:
The device itself is class. Can be easily operated with gloves, easy to read display, all the functions you could want and good optics (in white / black / red wheel).

However, I have the equipment bought myself primarily to measure cadence and pulse. Otherwise, I use a Garmin 605, but just pulse and TF can not.
TF is great, but the thing with the pulse was with me a story full of misunderstandings ... has something to do with blood.

Some tours everything worked as it should. From start to finish through pulse measurement and display. As a rule, it was so that the pulse measurement functioned only partially. Either did only after the halfway something or not, or from time to time.

As I said, 2 computers and 3 chest straps through. To the surrounding conditions, it may not have been, I am one years rumgeschlagen so.
For running, I use a Polar and since everything works as it should. On the MTB I also have a polar and also all good. So I know how to put on a chest strap and how to handle it (moisten etc).
However, I noticed that the measurement points are quite "dense" to each other. I have well over a meter a pretty powerful chest and I am afraid that it has something to do with. The front part of the belt with the measurement points is a bit "short" for me. Even if I so closely adjusting the belt that I could do but certainly not endurance sports so maybe measure, the seat is not optimal.

So are all rather more stable in the chest area: Try the unit times out if it does. With me are there from the beginning 5-10 minutes passed. Actually, between every measurement times for a few seconds away. Unfortunately, they never did come back well.

Except for this shortcoming - certainly one of the best cycling computer in the price segment.