diff --git a/devtools/client/netmonitor/src/actions/ui.js b/devtools/client/netmonitor/src/actions/ui.js
index 8346a829f791..05b15b8e185e 100644
--- a/devtools/client/netmonitor/src/actions/ui.js
+++ b/devtools/client/netmonitor/src/actions/ui.js
@@ -7,7 +7,6 @@
 const {
   ACTIVITY_TYPE,
   OPEN_NETWORK_DETAILS,
-  RESIZE_NETWORK_DETAILS,
   ENABLE_PERSISTENT_LOGS,
   DISABLE_BROWSER_CACHE,
   OPEN_STATISTICS,
@@ -29,20 +28,6 @@ function openNetworkDetails(open) {
   };
 }
 
-/**
- * Change network details panel size.
- *
- * @param {integer} width
- * @param {integer} height
- */
-function resizeNetworkDetails(width, height) {
-  return {
-    type: RESIZE_NETWORK_DETAILS,
-    width,
-    height,
-  };
-}
-
 /**
  * Change persistent logs state.
  *
@@ -161,7 +146,6 @@ function toggleStatistics(connector) {
 
 module.exports = {
   openNetworkDetails,
-  resizeNetworkDetails,
   enablePersistentLogs,
   disableBrowserCache,
   openStatistics,
diff --git a/devtools/client/netmonitor/src/assets/styles/RequestList.css b/devtools/client/netmonitor/src/assets/styles/RequestList.css
index 100ad21e04ee..e24749c11057 100644
--- a/devtools/client/netmonitor/src/assets/styles/RequestList.css
+++ b/devtools/client/netmonitor/src/assets/styles/RequestList.css
@@ -65,6 +65,7 @@
 .requests-list-contents {
   display: table-row-group;
   position: absolute;
+  width: 100%;
   overflow-x: hidden;
   overflow-y: auto;
   --timings-scale: 1;
diff --git a/devtools/client/netmonitor/src/components/MonitorPanel.js b/devtools/client/netmonitor/src/components/MonitorPanel.js
index e671677301b7..f93a4e730b14 100644
--- a/devtools/client/netmonitor/src/components/MonitorPanel.js
+++ b/devtools/client/netmonitor/src/components/MonitorPanel.js
@@ -40,7 +40,6 @@ class MonitorPanel extends Component {
       isEmpty: PropTypes.bool.isRequired,
       networkDetailsOpen: PropTypes.bool.isRequired,
       openNetworkDetails: PropTypes.func.isRequired,
-      onNetworkDetailsResize: PropTypes.func.isRequired,
       request: PropTypes.object,
       selectedRequestVisible: PropTypes.bool.isRequired,
       sourceMapService: PropTypes.object,
@@ -57,7 +56,6 @@ class MonitorPanel extends Component {
     };
 
     this.onLayoutChange = this.onLayoutChange.bind(this);
-    this.onNetworkDetailsResized = this.onNetworkDetailsResized.bind(this);
   }
 
   componentDidMount() {
@@ -96,16 +94,6 @@ class MonitorPanel extends Component {
     });
   }
 
-  onNetworkDetailsResized(width, height) {
-   // Cleaning width and height parameters, because SplitBox passes ALWAYS two values,
-   // while depending on orientation ONLY ONE dimension is managed by it at a time.
-    let { isVerticalSpliter }  = this.state;
-      return this.props.onNetworkDetailsResized(
-        isVerticalSpliter ? width : null,
-        isVerticalSpliter ? null : height
-      )
-  }
-
   render() {
     let {
       connector,
@@ -140,7 +128,6 @@ class MonitorPanel extends Component {
           endPanelCollapsed: !networkDetailsOpen,
           endPanelControl: true,
           vert: this.state.isVerticalSpliter,
-          onControlledPanelResized: this.onNetworkDetailsResized,
         }),
       )
     );
@@ -156,9 +143,6 @@ module.exports = connect(
   }),
   (dispatch) => ({
     openNetworkDetails: (open) => dispatch(Actions.openNetworkDetails(open)),
-    onNetworkDetailsResized: (width, height) => dispatch(
-      Actions.resizeNetworkDetails(width, height)
-    ),
     updateRequest: (id, data, batch) => dispatch(Actions.updateRequest(id, data, batch)),
   }),
 )(MonitorPanel);
diff --git a/devtools/client/netmonitor/src/components/RequestListContent.js b/devtools/client/netmonitor/src/components/RequestListContent.js
index 4d513402b9ac..4046d817dc79 100644
--- a/devtools/client/netmonitor/src/components/RequestListContent.js
+++ b/devtools/client/netmonitor/src/components/RequestListContent.js
@@ -50,9 +50,6 @@ class RequestListContent extends Component {
     return {
       connector: PropTypes.object.isRequired,
       columns: PropTypes.object.isRequired,
-      networkDetailsOpen: PropTypes.bool.isRequired,
-      networkDetailsWidth: PropTypes.number.isRequired,
-      networkDetailsHeight: PropTypes.number.isRequired,
       cloneSelectedRequest: PropTypes.func.isRequired,
       displayedRequests: PropTypes.array.isRequired,
       firstRequestStartedMillis: PropTypes.number.isRequired,
@@ -117,12 +114,6 @@ class RequestListContent extends Component {
       // Using maximum scroll height rather than node.scrollHeight to avoid sync reflow.
       node.scrollTop = MAX_SCROLL_HEIGHT;
     }
-    if (prevProps.networkDetailsOpen !== this.props.networkDetailsOpen ||
-      prevProps.networkDetailsWidth !== this.props.networkDetailsWidth ||
-      prevProps.networkDetailsHeight !== this.props.networkDetailsHeight
-    ) {
-      this.onResize();
-    }
   }
 
   componentWillUnmount() {
@@ -135,7 +126,6 @@ class RequestListContent extends Component {
 
   onResize() {
     let parent = this.refs.contentEl.parentNode;
-    this.refs.contentEl.style.width = parent.offsetWidth + "px";
     this.refs.contentEl.style.height = parent.offsetHeight + "px";
   }
 
@@ -310,9 +300,6 @@ class RequestListContent extends Component {
 module.exports = connect(
   (state) => ({
     columns: state.ui.columns,
-    networkDetailsOpen: state.ui.networkDetailsOpen,
-    networkDetailsWidth: state.ui.networkDetailsWidth,
-    networkDetailsHeight: state.ui.networkDetailsHeight,
     displayedRequests: getDisplayedRequests(state),
     firstRequestStartedMillis: state.requests.firstStartedMillis,
     selectedRequest: getSelectedRequest(state),
diff --git a/devtools/client/netmonitor/src/constants.js b/devtools/client/netmonitor/src/constants.js
index b3c512b85347..58b854137fe8 100644
--- a/devtools/client/netmonitor/src/constants.js
+++ b/devtools/client/netmonitor/src/constants.js
@@ -14,7 +14,6 @@ const actionTypes = {
   CLONE_SELECTED_REQUEST: "CLONE_SELECTED_REQUEST",
   ENABLE_REQUEST_FILTER_TYPE_ONLY: "ENABLE_REQUEST_FILTER_TYPE_ONLY",
   OPEN_NETWORK_DETAILS: "OPEN_NETWORK_DETAILS",
-  RESIZE_NETWORK_DETAILS: "RESIZE_NETWORK_DETAILS",
   ENABLE_PERSISTENT_LOGS: "ENABLE_PERSISTENT_LOGS",
   DISABLE_BROWSER_CACHE: "DISABLE_BROWSER_CACHE",
   OPEN_STATISTICS: "OPEN_STATISTICS",
diff --git a/devtools/client/netmonitor/src/reducers/ui.js b/devtools/client/netmonitor/src/reducers/ui.js
index c3bea1389fd2..8797f1e59261 100644
--- a/devtools/client/netmonitor/src/reducers/ui.js
+++ b/devtools/client/netmonitor/src/reducers/ui.js
@@ -8,7 +8,6 @@ const Services = require("Services");
 const {
   CLEAR_REQUESTS,
   OPEN_NETWORK_DETAILS,
-  RESIZE_NETWORK_DETAILS,
   ENABLE_PERSISTENT_LOGS,
   DISABLE_BROWSER_CACHE,
   OPEN_STATISTICS,
@@ -56,8 +55,6 @@ function UI(initialState = {}) {
     columns: Columns(),
     detailsPanelSelectedTab: PANELS.HEADERS,
     networkDetailsOpen: false,
-    networkDetailsWidth: null,
-    networkDetailsHeight: null,
     persistentLogsEnabled: Services.prefs.getBoolPref("devtools.netmonitor.persistlog"),
     browserCacheDisabled: Services.prefs.getBoolPref("devtools.cache.disabled"),
     statisticsOpen: false,
@@ -87,14 +84,6 @@ function openNetworkDetails(state, action) {
   };
 }
 
-function resizeNetworkDetails(state, action) {
-  return {
-    ...state,
-    networkDetailsWidth: action.width,
-    networkDetailsHeight: action.height,
-  };
-}
-
 function enablePersistentLogs(state, action) {
   return {
     ...state,
@@ -145,8 +134,6 @@ function ui(state = UI(), action) {
       return openNetworkDetails(state, { open: false });
     case OPEN_NETWORK_DETAILS:
       return openNetworkDetails(state, action);
-    case RESIZE_NETWORK_DETAILS:
-      return resizeNetworkDetails(state, action);
     case ENABLE_PERSISTENT_LOGS:
       return enablePersistentLogs(state, action);
     case DISABLE_BROWSER_CACHE: