Variable WiFi sensitivity

[Susan_Barlow]

Hi. I have three M5AtomS3 lite units. Two of them are fine, but one appears to be a bit deaf when it comes to WiFi. I've also got two M5AtomS3 units with screens. Again, one is fine, and the second one appears to give poor results.
I've run some WiFi scan tests on all 5 using the following code:

#include <WiFi.h>

void setup() {
  USBSerial.begin(115200);
  WiFi.mode(WIFI_STA);
  WiFi.disconnect();
}

void loop() {    
  int16_t NetworkCount;
  static uint8_t ctr=0;
  NetworkCount = WiFi.scanNetworks(false,true,true);
  USBSerial.printf("%2d ",NetworkCount);
  vTaskDelay(5000);
  ctr++;
  if(ctr==10) {
    USBSerial.printf("\n");
    while(true);
  }
}

This gives me the following results:

• AtomS3: 14 16 16 15 19 17 17 15 15 13
• AtomS3: 7 7 8 8 8 9 7 9 8 10
• AtomS3 lite: 20 16 20 18 17 17 18 19 16 17
• AtomS3 Lite: 19 20 21 24 19 20 18 20 18 21
• AtomS3 Lite: 4 4 4 4 4 4 4 4 4 4

As a control reference, I get these results from an ESP32S3Pro

• ProS3: 23 23 23 23 24 25 21 21 19 21

I'm not bothered that a ProS3 finds more networks, but am puzzled by the significant drop off with the two Atoms. Has anyone come across this issue before? Is there any sort of fix for the deaf units, or might this just be a batch production issue?
Many thanks,
Susan