@ninjatill. That brings up a really good point. The Argon has 2 antenna connectors. I was just activating the Mesh antenna, I did not actually connect two antennas.
The coding is here:
The important code I have pasted below:
void selectExternalMeshAntenna() {
#if (PLATFORM_ID == PLATFORM_ARGON)
digitalWrite(ANTSW1, 1);
digitalWrite(ANTSW2, 0);
#elif (PLATFORM_ID == PLATFORM_BORON)
digitalWrite(ANTSW1, 0);
#else
digitalWrite(ANTSW1, 0);
digitalWrite(ANTSW2, 1);
#endif
}
What was here has been deleted after @ninjatill and @rickkas7 explanation.