Index: sources/bluetooth/BluetoothInterface.cpp
===================================================================
diff -u -rc9f8f8cf3c6c37fc6460d8675c62c9442c4d4263 -r9dd6d10ac1164c651e8d536673641d1e90981207
--- sources/bluetooth/BluetoothInterface.cpp	(.../BluetoothInterface.cpp)	(revision c9f8f8cf3c6c37fc6460d8675c62c9442c4d4263)
+++ sources/bluetooth/BluetoothInterface.cpp	(.../BluetoothInterface.cpp)	(revision 9dd6d10ac1164c651e8d536673641d1e90981207)
@@ -1,4 +1,4 @@
-/*!
+/*!
  *
  * Copyright (c) 2021-2023 Diality Inc. - All Rights Reserved.
  * \copyright
@@ -413,6 +413,10 @@
     initConnections();
     NOTIFY_LOCAL_INIT
     NOTIFY_IDLE
+
+    // The initial scan to populate the bt device list
+    // opting to not quitDevice to hold previous paired status
+    startScan(false);
 }
 
 /*!
@@ -422,7 +426,8 @@
  */
 void BluetoothInterface::ondoScan()
 {
-    startScan();
+    // Re-scanning, opting to unpair to last device
+    startScan(true);
 }
 
 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -476,7 +481,18 @@
             BluetoothDeviceData  data;
             data.addr = vInfo.address().toString();
             data.name = vInfo.name();
-            data.pair = _local->pairingStatus(vInfo.address());
+
+            bool isPaired     = _local->pairingStatus(vInfo.address()) == QBluetoothLocalDevice::Paired;
+            bool isAuthPaired = _local->pairingStatus(vInfo.address()) == QBluetoothLocalDevice::AuthorizedPaired;
+
+            data.pair = isPaired || isAuthPaired;
+
+            if ( data.pair ) {
+                // If a previously paired device is found, sdo initial connecting to it
+                _temp = QBluetoothDeviceInfo(vInfo.address(), vInfo.name(), QBluetoothDeviceInfo::HealthBloodPressureMonitor);
+                connectToDevice();
+            }
+
             emit didDeviceChange(data);
             NOTIFY_SCAN_FOUND
         }
@@ -525,6 +541,18 @@
  */
 void BluetoothInterface::onDeviceSelect(const BluetoothDeviceData &vDevice) {
     stopScan();
+
+    if ( isLocalValid() && isDeviceValid() ){
+        // Check pair status, if connected to a bt device already, disconnect before connecting to selected
+        // bt device to avoid "device connection error"
+        bool isPaired = _local->pairingStatus(_device->remoteAddress()) == QBluetoothLocalDevice::Paired;
+        bool isAuthPaired = _local->pairingStatus(_device->remoteAddress()) == QBluetoothLocalDevice::AuthorizedPaired;
+        if ( isPaired || isAuthPaired ) {
+            quitDevice();
+        }
+    }
+
+    // Proceed to connect to selected device
     _temp = QBluetoothDeviceInfo(QBluetoothAddress(vDevice.addr), vDevice.name, QBluetoothDeviceInfo::HealthBloodPressureMonitor);
     connectToDevice();
 }
@@ -580,6 +608,21 @@
  */
 void BluetoothInterface::onDeviceError(QLowEnergyController::Error vError)
 {
+    //DEBUG: qDebug()<< "Device Error " << vError;
+    bool isErrorUnknown = (vError == QLowEnergyController::UnknownError);
+    if ( isErrorUnknown ) {
+        // When polling to reconnect to the remote device, the application encounters an unknown
+        // error  occasionally when the connection fails, but does not report it as a connection error
+
+        bool isLocalAndDeviceValid = isLocalValid() && isDeviceValid();
+        if ( isLocalAndDeviceValid && ( _local->pairingStatus(_device->remoteAddress()) != QBluetoothLocalDevice::Unpaired ) ) {
+            // Code is opting to set _reconnectionActive to true to allow polling to continue since the device
+            // is still paired and the error encountered is due to not being able to connect to the remote device.
+            _reconnectionActive = true;
+            //DEBUG: qDebug()<< "unknown error : reconnection set to true";
+        }
+    }
+
     // if the device is trying to connect to the previously paired device and the device was not on at this moment it should go to the reconnection state.
     if ( _tryingrepairActive ) _reconnectionActive = true;
 
@@ -785,9 +828,10 @@
 /*!
  * \brief   BluetoothInterface::startScan
  * \details Stars the agent device scan
+ * \param   vQuitDevice - true if quitting device, else scan only
  * \return  true if the agent can successfully start the scan.
  */
-bool BluetoothInterface::startScan()
+bool BluetoothInterface::startScan(bool vQuitDevice)
 {
     if ( ! isValid() ) return false; // POST failed.
 
@@ -797,7 +841,11 @@
     }
 
     NOTIFY_SCAN_START
-    quitDevice();
+
+    if (vQuitDevice) {
+        quitDevice();
+    }
+
     _agent->start(QBluetoothDeviceDiscoveryAgent::LowEnergyMethod);
     return true;
 }