MAC address received using ESP-Now... always the same?

[fmotta]

I am writing an application which handles several ESP-Now senders.
Station ID is OK.
But, I wanted to filter by MAC address.

Using the standard code to get the WiFi mac addresses I have 3 different MACs (obscured):
RCV:ESP Board MAC Address: 8c:4f:00:37:ZZ:ZZ
SDN2:ESP Board MAC Address: 8c:4f:00:37:XX:XX
SND1:ESP Board MAC Address: 8c:4f:00:36:YY:YY

These are all different (remember the last 2 octets above are obscured.. .but are valid in reality).

RCV is getting messages from both SDN1 & SDN2. Yet the MAC address is ALWAYS the same (below is obscured last two octets):
7a:c1:fb:3f:RR:RR

Why am I getting only ONE MAC address which is NOT the one from the sender nor receiver?
How do I get the correct senders MAC address?

Code snippet:

void OnDataRecv(const uint8_t * mac_addr, const uint8_t *incomingData, int len) {
char macStr[18];
Serial.print("Packet received from: ");
snprintf(macStr, sizeof(macStr), "%02x:%02x:%02x:%02x:%02x:%02x",
mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_addr[4], mac_addr[5]);
Serial.println(macStr);


Thanks