diff --git a/src/domain/session/room/timeline/TimelineViewModel.js b/src/domain/session/room/timeline/TimelineViewModel.js
index 8ff6b09e..31be88ac 100644
--- a/src/domain/session/room/timeline/TimelineViewModel.js
+++ b/src/domain/session/room/timeline/TimelineViewModel.js
@@ -53,6 +53,12 @@ export class TimelineViewModel extends ViewModel {
         let hasSeenUpdate = false;
         const checkForUpdate = (idx, tile) => {
             if (tile.shape !== "gap") {
+                /*
+                It's possible that this method executes before the GapTile has been rendered,
+                so don't count the GapTile as an update.
+                Usually happens when onScroll() is triggered by a non-timeline UI change,
+                eg: SessionStatusView being rendered
+                 */
                 hasSeenUpdate = true;
             }
         }