Removed some code written to recover from a strange connection error because it didn't work as expected. The temporary fix I did is to make a preventive MCU reset every 5 hours or when the connection error appears, until I can find the cause of it.

src/app/app.ino

@@ -22,6 +22,7 @@
 #define CHAN 108   //0-125
 #define RECV_CHECK 5000 //We test every 5s if we received something
 #define WIFI_CHECK_TIMEOUT 20000
+#define PREVENTIVE_RESET_DELAY 18000000 //Every 5 hours
 
 uint8_t payload[32] = {0};
 DataPacket dp;
@@ -39,11 +40,13 @@ HttpClient DBHost(DB_SERVER, PATH);
 Dictionary<DictionaryHelper::StringEntity> weatherStationPostData, mailboxPostData;
 
 const uint8_t ADDR[] = "WEST1", ADDR2[] = "ABCDE";
-uint64_t timeStamp(0), irqSaver(0);
+uint32_t timeStamp(0), irqSaver(0), resetTimeStamp(0);
 uint32_t freeMem(0);
 uint16_t biggestContigMemBlock(0);
 uint8_t frag(0);
+int insertIntoDBError(0);
 volatile boolean IRQFlag(false);
+boolean waitingForResetSignal(false), resetNow(false);
 
 IRAM_ATTR void NRFIRQsHandler(void *p)
 {
@@ -158,19 +161,21 @@ void loop()
           {
             memcpy(&wsdp, payload, sizeof(wsdp));
             debugStruct(&wsdp);
-            insertIntoDB(&wsdp);
+            insertIntoDBError = insertIntoDB(&wsdp);
           }
             break;
           case CONNECTED_MAILBOX:
           {
             memcpy(&mdp, payload, sizeof(mdp));
             debugStruct(&mdp);
-            insertIntoDB(&mdp);
+            insertIntoDBError = insertIntoDB(&mdp);
           }
             break;
           default:
             break;
         }
+
+        if(waitingForResetSignal)resetNow = true;
       }
     }
     
@@ -201,19 +206,21 @@ void loop()
           {
             memcpy(&wsdp, payload, sizeof(wsdp));
             debugStruct(&wsdp);
-            insertIntoDB(&wsdp);
+            insertIntoDBError = insertIntoDB(&wsdp);
           }
             break;
           case CONNECTED_MAILBOX:
           {
             memcpy(&mdp, payload, sizeof(mdp));
             debugStruct(&mdp);
-            insertIntoDB(&mdp);
+            insertIntoDBError = insertIntoDB(&mdp);
           }
             break;
           default:
             break;
         }
+
+        if(waitingForResetSignal)resetNow = true;
       }
     }
 
@@ -254,6 +261,19 @@ void loop()
     }
     timeStamp = millis();
   }
+
+  //Here we handle the reset
+  if(millis() - resetTimeStamp > PREVENTIVE_RESET_DELAY)
+  {
+    Serial.println("Waiting next payload before resetting MCU :( !");
+    waitingForResetSignal = true;
+    resetTimeStamp = millis();
+  }
+
+  if((waitingForResetSignal && resetNow) || insertIntoDBError == -125)
+  {
+    ESP.reset();
+  }
 }
 
 /**
@@ -271,7 +291,7 @@ void lostConnectionFunc(const WiFiEventStationModeDisconnected &event)
   Serial.println("Lost connection, will try to reconnect ...");
 }
 
-void insertIntoDB(WeatherStationDataPacket *p)
+int insertIntoDB(WeatherStationDataPacket *p)
 {
   char buffer[100] = "";
   int result(0);
@@ -309,27 +329,10 @@ void insertIntoDB(WeatherStationDataPacket *p)
    else
    {
     Serial.printf("Failed to post data : error(%d)\n", result);
-    if(result == -125)
-    {
-      WiFi.disconnect();
-      WiFi.begin(SSID, PWD);
-
-      while(!WiFi.isConnected())
-      {
-        Serial.println("Reconnecting !");
-      }
-      if((result = DBHost.sendHttpQuery(HttpClient::HttpRequestMethod::POST, NULL, &weatherStationPostData)) == 0)
-      {
-        HttpClient::HTTP_CODE response = DBHost.isReplyAvailable(2000);
-        Serial.printf("Second send got response code : %u\n", response);
-      }
-      else
-      {
-        Serial.printf("Second send failed to post data : error(%d)\n", result);
-      }
-    }
    }
    DBHost.stop();
+
+   return result;
 }
 
 void debugStruct(WeatherStationDataPacket *p)
@@ -367,7 +370,7 @@ void debugStruct(WeatherStationDataPacket *p)
   Serial.println(" *C");
 }
 
-void insertIntoDB(MailboxDataPacket *p)
+int insertIntoDB(MailboxDataPacket *p)
 {
   char buffer[100] = "";
   int result(0);
@@ -404,6 +407,8 @@ void insertIntoDB(MailboxDataPacket *p)
     Serial.printf("Failed to post data : error(%d)\n", result);
    }
    DBHost.stop();
+
+   return result;
 }
 
 void debugStruct(MailboxDataPacket *p)