SNR heatmap bug

Hi

I think I´ve found a bug in the “troubleshooting – SNR” heatmap or I´m misunderstanding something.

I´ve done a site survey at work with 22 samples and a site survey at my small home apartment with 3 samples. Both surveys in netspot reporter shows that almost all of the area is RED on the signal-to-noise-ratio (SNR) troubleshooting heat map and the help text says that is indicating serious problems.
However none of these networks have stability issues and they all are performing well.

So then I tested also with “Wifi Explorer” and that application says SNR is good and typically SNR is at from 20 to 60 db.
Wifi explorer: https://itunes.apple.com/no/app/wifi-explorer/id494803304?mt=12

Your help page about SNR says the 25 to 40 is good and above is excellent. So why then is most of my map red for bad SNR when other tools says the SNR is from 20 to 60 db?
/help/what-is-the-signal-to-noise/

I then went back to study the Netspot Reporter Survey data and found that at one of the measurement points in a meeting room 50 cm from the AP sender the signal-to-noise ratio to that sender is listed by Netspot survey as -49db when I hover over that measurement point? I would have expected a positive number of 20-40?

So I go the same spot and measure with Wifi explorer and it says:
signal quality: good 65-75%
Noise: 7-11%
SNR: 31-38 db

Am I misunderstanding your application that seems to say I have very bad SNR at every wifi spot I use daily or is it wifi explorer that is reporting incorrectly a good SNR? quite confusing with such opposite results in same areas at same times with the same Macbook.

Some details:
At the office we are using 11 Cisco Meraki MR34 Access Points and there are many other company networks there at the higher and lower floors. Office is open office landscape type but with closed meeting rooms (but I chose apartment/closed office type for scan). I´ve only test measured one of our floors that have 4 APs but there are also other Meraki APs at our other floors above and under. I used my new Macbook for the measurements. There are almost no people here now because of summer vacation so not many clients.

At home I have a single Linksys AC 5 ghz small business class AP that has been performing well for several months but Netspot says it should have huge problems with SNR in the site survey which is very strange.

So am I misunderstanding the red SNR troubleshooting heat map?