diff --git a/sonic_platform_base/sonic_xcvr/api/public/sff8436.py b/sonic_platform_base/sonic_xcvr/api/public/sff8436.py
index 0539becc1..37b1ef0d1 100644
--- a/sonic_platform_base/sonic_xcvr/api/public/sff8436.py
+++ b/sonic_platform_base/sonic_xcvr/api/public/sff8436.py
@@ -217,6 +217,8 @@ def get_transceiver_threshold_info(self):
         }
 
     def get_rx_los(self):
+        if not self.get_rx_los_support():
+            return ["N/A" for _ in range(self.NUM_CHANNELS)]
         rx_los = self.xcvr_eeprom.read(consts.RX_LOS_FIELD)
         if rx_los is None:
             return None
@@ -269,6 +271,8 @@ def get_voltage(self):
         return float("{:.3f}".format(voltage))
 
     def get_tx_bias(self):
+        if not self.get_tx_bias_support():
+            return ["N/A" for _ in range(self.NUM_CHANNELS)]
         tx_bias = self.xcvr_eeprom.read(consts.TX_BIAS_FIELD)
         if tx_bias is None:
             return None
@@ -342,10 +346,10 @@ def get_voltage_support(self):
         return not self.is_copper()
 
     def get_rx_los_support(self):
-        return True
+        return not self.is_copper()
 
     def get_tx_bias_support(self):
-        return True
+        return not self.is_copper()
 
     def get_tx_fault_support(self):
         return self.xcvr_eeprom.read(consts.TX_FAULT_SUPPORT_FIELD)
diff --git a/sonic_platform_base/sonic_xcvr/api/public/sff8636.py b/sonic_platform_base/sonic_xcvr/api/public/sff8636.py
index 108258786..800367581 100644
--- a/sonic_platform_base/sonic_xcvr/api/public/sff8636.py
+++ b/sonic_platform_base/sonic_xcvr/api/public/sff8636.py
@@ -235,6 +235,8 @@ def get_transceiver_threshold_info(self):
         }
 
     def get_rx_los(self):
+        if not self.get_rx_los_support():
+            return ["N/A" for _ in range(self.NUM_CHANNELS)]
         rx_los = self.xcvr_eeprom.read(consts.RX_LOS_FIELD)
         if rx_los is None:
             return None
@@ -287,6 +289,8 @@ def get_voltage(self):
         return float("{:.3f}".format(voltage))
 
     def get_tx_bias(self):
+        if not self.get_tx_bias_support():
+            return ["N/A" for _ in range(self.NUM_CHANNELS)]
         tx_bias = self.xcvr_eeprom.read(consts.TX_BIAS_FIELD)
         if tx_bias is None:
             return None
@@ -395,10 +399,10 @@ def get_voltage_support(self):
         return self._voltage_support
 
     def get_rx_los_support(self):
-        return True
+        return not self.is_copper()
 
     def get_tx_bias_support(self):
-        return True
+        return not self.is_copper()
 
     def get_tx_fault_support(self):
         return self.xcvr_eeprom.read(consts.TX_FAULT_SUPPORT_FIELD)
diff --git a/tests/sonic_xcvr/test_sff8436.py b/tests/sonic_xcvr/test_sff8436.py
index 3d209cf37..262df1f68 100644
--- a/tests/sonic_xcvr/test_sff8436.py
+++ b/tests/sonic_xcvr/test_sff8436.py
@@ -101,11 +101,14 @@ def test_is_copper(self):
     def test_simulate_copper(self):
         with patch.object(self.api, 'is_copper', return_value=True):
             assert self.api.get_rx_power() == ['N/A'] * self.api.NUM_CHANNELS
+            assert self.api.get_tx_bias() == ['N/A'] * self.api.NUM_CHANNELS
+            assert self.api.get_rx_los() == ['N/A'] * self.api.NUM_CHANNELS
             assert self.api.get_module_temperature() == 'N/A'
             assert self.api.get_voltage() == 'N/A'
             assert not self.api.get_tx_power_support()
             assert not self.api.get_rx_power_support()
-            assert not self.api.get_rx_power_support()
+            assert not self.api.get_tx_bias_support()
+            assert not self.api.get_rx_los_support()
             assert not self.api.get_temperature_support()
             assert not self.api.get_voltage_support()
 
diff --git a/tests/sonic_xcvr/test_sff8636.py b/tests/sonic_xcvr/test_sff8636.py
index 9d06dbaff..67133e4d3 100644
--- a/tests/sonic_xcvr/test_sff8636.py
+++ b/tests/sonic_xcvr/test_sff8636.py
@@ -103,9 +103,12 @@ def test_is_copper(self):
     def test_simulate_copper(self):
         with patch.object(self.api, 'is_copper', return_value=True):
             assert self.api.get_rx_power() == ['N/A'] * self.api.NUM_CHANNELS
+            assert self.api.get_tx_bias() == ['N/A'] * self.api.NUM_CHANNELS
+            assert self.api.get_rx_los() == ['N/A'] * self.api.NUM_CHANNELS
             assert not self.api.get_tx_power_support()
             assert not self.api.get_rx_power_support()
-            assert not self.api.get_rx_power_support()
+            assert not self.api.get_tx_bias_support()
+            assert not self.api.get_rx_los_support()
             assert not self.api.get_temperature_support()
             assert not self.api.get_voltage_support()