It is possible for NetMonitor to show the correct LTE site. But if it does, it's just coincidental. Kind of like how a broken clock is coincidentally correct twice per day.
I will also add this little nugget. NetMonitor is more likely to be correct with a really strong LTE signal. Because if you have a really strong LTE signal, you are likely really close to the live site. And if you are really close to a live site with LTE, the chances of your device being on the same site for 1x are much, much higher. Not 100%, but more likely.
Robert