diff --git a/lib/logitech_receiver/device.py b/lib/logitech_receiver/device.py
index e964d41c..93a9d744 100644
--- a/lib/logitech_receiver/device.py
+++ b/lib/logitech_receiver/device.py
@@ -714,6 +714,17 @@ class Device:
 
         timeout = base.DEFAULT_TIMEOUT
         with base.acquire_timeout(base.handle_lock(handle), handle, timeout):
+            # Log the outgoing sub-message at INFO so field diagnostics can
+            # correlate bridge NACKs with the exact payload we sent (e.g. to
+            # verify mic-gain byte landed in the device's accepted range).
+            if logger.isEnabledFor(logging.INFO):
+                logger.info(
+                    "bridge TX: sub_idx=%d func=0x%02X sw_id=%d payload=%s",
+                    sub_feat_idx,
+                    sub_function,
+                    sw_id,
+                    sub_params.hex() if sub_params else "",
+                )
             if sub_len <= first_chunk:
                 # Single-frame path
                 layer3 = bridge_prefix + bridge_hdr + sub_msg
diff --git a/lib/logitech_receiver/settings_templates.py b/lib/logitech_receiver/settings_templates.py
index 066634fc..cb92a323 100644
--- a/lib/logitech_receiver/settings_templates.py
+++ b/lib/logitech_receiver/settings_templates.py
@@ -1680,12 +1680,19 @@ class HeadsetMicGain(settings.Setting):
         # LGHUB caches these once at startup to rescale SetMicGain writes.
         try:
             info = device.feature_request(cls.feature, 0x00)
-        except Exception:
+        except Exception as e:
+            logger.info("HeadsetMicGain: GetInfo raised %s, using fallback int8 range", e)
             info = None
         if info and len(info) >= 2:
             min_gain = struct.unpack("b", bytes([info[0]]))[0]
             max_gain = struct.unpack("b", bytes([info[1]]))[0]
             if max_gain <= min_gain:  # sanity — fall back to class defaults
+                logger.info(
+                    "HeadsetMicGain: GetInfo returned nonsense range [%d, %d] (hex=%s), using fallback int8 range",
+                    min_gain,
+                    max_gain,
+                    info.hex(),
+                )
                 min_gain, max_gain = cls.min_value, cls.max_value
             else:
                 logger.info(
@@ -1694,6 +1701,10 @@ class HeadsetMicGain(settings.Setting):
                     max_gain,
                 )
         else:
+            logger.info(
+                "HeadsetMicGain: GetInfo returned %s, using fallback int8 range",
+                info.hex() if info else info,
+            )
             min_gain, max_gain = cls.min_value, cls.max_value
         rw = settings.FeatureRW(cls.feature, **cls.rw_options)
         validator = settings_validator.RangeValidator(min_value=min_gain, max_value=max_gain, byte_count=1, signed=True)