--- a/devtools/client/netmonitor/src/components/RequestListContent.js
+++ b/devtools/client/netmonitor/src/components/RequestListContent.js
@@ -90,40 +90,33 @@ class RequestListContent extends Compone
   }
 
   componentDidMount() {
     // Install event handler for displaying a tooltip
     this.tooltip.startTogglingOnHover(this.refs.contentEl, this.onHover, {
       toggleDelay: REQUESTS_TOOLTIP_TOGGLE_DELAY,
       interactive: true
     });
-    // Everytime the list is created or pruned, re-enable scroll to bottom feature.
-    this.shouldScrollToBottom = true;
-
     // Install event handler to hide the tooltip on scroll
     this.refs.contentEl.addEventListener("scroll", this.onScroll, true);
     this.onResize();
   }
 
-  componentDidUpdate(prevProps) {
-    if (!this.shouldScrollToBottom) {
-      return;
-    }
+  componentWillUpdate(nextProps) {
     // Check if the list is scrolled to bottom before the UI update.
     // The scroll is ever needed only if new rows are added to the list.
-    const hasNewRequests = this.props.displayedRequests.size -
-      prevProps.displayedRequests.size > 0;
+    const delta = nextProps.displayedRequests.size - this.props.displayedRequests.size;
+    this.shouldScrollBottom = delta > 0 && this.isScrolledToBottom();
+  }
+
+  componentDidUpdate(prevProps) {
+    let node = this.refs.contentEl;
     // Keep the list scrolled to bottom if a new row was added
-    if (hasNewRequests) {
-      // Set a boolean flag to help `scroll` listener to know that the next event
-      // is related to the scroll to bottom and can be ignored.
-      this.ignoreNextScroll = true;
-
+    if (this.shouldScrollBottom && node.scrollTop !== MAX_SCROLL_HEIGHT) {
       // Using maximum scroll height rather than node.scrollHeight to avoid sync reflow.
-      let node = this.refs.contentEl;
       node.scrollTop = MAX_SCROLL_HEIGHT;
     }
   }
 
   componentWillUnmount() {
     this.refs.contentEl.removeEventListener("scroll", this.onScroll, true);
 
     // Uninstall the tooltip event handler
@@ -195,24 +188,16 @@ class RequestListContent extends Compone
     return itemEl.querySelector(".requests-list-file");
   }
 
   /**
    * Scroll listener for the requests menu view.
    */
   onScroll() {
     this.tooltip.hide();
-
-    // Ignore scroll related to new requests being displayed
-    // To prevent slow reflows done in isScrolledToBottom.
-    if (this.ignoreNextScroll) {
-      this.ignoreNextScroll = false;
-      return;
-    }
-    this.shouldScrollToBottom = this.isScrolledToBottom();
   }
 
   /**
    * Handler for keyboard events. For arrow up/down, page up/down, home/end,
    * move the selection up or down.
    */
   onKeyDown(evt) {
     let delta;
@@ -254,17 +239,17 @@ class RequestListContent extends Compone
     this.contextMenu.open(evt, selectedRequest, sortedRequests);
   }
 
   /**
    * If selection has just changed (by keyboard navigation), don't keep the list
    * scrolled to bottom, but allow scrolling up with the selection.
    */
   onFocusedNodeChange() {
-    this.shouldScrollToBottom = false;
+    this.shouldScrollBottom = false;
   }
 
   render() {
     const {
       connector,
       columns,
       displayedRequests,
       firstRequestStartedMillis,
@@ -280,19 +265,17 @@ class RequestListContent extends Compone
     return (
       div({ className: "requests-list-wrapper" },
         div({ className: "requests-list-table" },
           div({
             ref: "contentEl",
             className: "requests-list-contents",
             tabIndex: 0,
             onKeyDown: this.onKeyDown,
-            // scale is null until the waterfall is initialized
-            style: { "--timings-scale": scale ? scale : 0,
-                     "--timings-rev-scale": (scale ? 1 / scale : 1) }
+            style: { "--timings-scale": scale, "--timings-rev-scale": 1 / scale }
           },
             RequestListHeader(),
             displayedRequests.map((item, index) => RequestListItem({
               firstRequestStartedMillis,
               fromCache: item.status === "304" || item.fromCache,
               connector,
               columns,
               item,

--- a/devtools/client/netmonitor/test/browser_net_autoscroll.js
+++ b/devtools/client/netmonitor/test/browser_net_autoscroll.js
@@ -36,21 +36,16 @@ add_task(function* () {
   // save for comparison later
   let scrollTop = requestsContainer.scrollTop;
   yield waitForNetworkEvents(monitor, 8);
   yield waitSomeTime();
   is(requestsContainer.scrollTop, scrollTop, "Did not scroll.");
 
   // (3) Now set the scroll position back at the bottom and check that
   // additional requests *do* cause the container to scroll down.
-  // Wait for another request to be displayed in order to ensure that
-  // scrollTop is set just before next RequestListContent.componentWillUpdate fires.
-  // If scrollTop is set between componentWillUpdate and componentDidUpdate,
-  // the view won't be scrolled.
-  yield waitForNetworkEvents(monitor, 8);
   requestsContainer.scrollTop = requestsContainer.scrollHeight;
   ok(scrolledToBottom(requestsContainer), "Set scroll position to bottom.");
   yield waitForNetworkEvents(monitor, 8);
   yield waitForScroll();
   ok(true, "Still scrolled to bottom.");
 
   // (4) Now select the first item in the list
   // and check that additional requests do not change the scroll position