diff --git a/homeassistant/components/knx/__init__.py b/homeassistant/components/knx/__init__.py
index 8a8e87b893f..0d039ca2c61 100644
--- a/homeassistant/components/knx/__init__.py
+++ b/homeassistant/components/knx/__init__.py
@@ -683,6 +683,7 @@ class KNXModule:
                 payload=GroupValueResponse(payload)
                 if attr_response
                 else GroupValueWrite(payload),
+                source_address=self.xknx.current_address,
             )
             await self.xknx.telegrams.put(telegram)
 
@@ -692,5 +693,6 @@ class KNXModule:
             telegram = Telegram(
                 destination_address=parse_device_group_address(address),
                 payload=GroupValueRead(),
+                source_address=self.xknx.current_address,
             )
             await self.xknx.telegrams.put(telegram)
diff --git a/homeassistant/components/knx/websocket.py b/homeassistant/components/knx/websocket.py
index a9da5036857..feb53ddc908 100644
--- a/homeassistant/components/knx/websocket.py
+++ b/homeassistant/components/knx/websocket.py
@@ -34,7 +34,7 @@ async def register_panel(hass: HomeAssistant) -> None:
         hass.http.register_static_path(
             URL_BASE,
             path,
-            cache_headers=not is_dev_build,
+            cache_headers=not is_dev_build(),
         )
         await panel_custom.async_register_panel(
             hass=hass,