diff --git a/changelog.d/5475.bugfix b/changelog.d/5475.bugfix
new file mode 100644
index 0000000000..03364f6a73
--- /dev/null
+++ b/changelog.d/5475.bugfix
@@ -0,0 +1 @@
+Fix some cases where the read marker line would not show up
diff --git a/vector/src/main/java/im/vector/app/features/home/room/detail/RoomDetailViewState.kt b/vector/src/main/java/im/vector/app/features/home/room/detail/RoomDetailViewState.kt
index 09b5211246..0c56d7e7eb 100644
--- a/vector/src/main/java/im/vector/app/features/home/room/detail/RoomDetailViewState.kt
+++ b/vector/src/main/java/im/vector/app/features/home/room/detail/RoomDetailViewState.kt
@@ -36,7 +36,7 @@ sealed class UnreadState {
     object Unknown : UnreadState()
     object HasNoUnread : UnreadState()
     data class ReadMarkerNotLoaded(val readMarkerId: String) : UnreadState()
-    data class HasUnread(val firstUnreadEventId: String) : UnreadState()
+    data class HasUnread(val firstUnreadEventId: String, val readMarkerId: String) : UnreadState()
 }
 
 data class JitsiState(
diff --git a/vector/src/main/java/im/vector/app/features/home/room/detail/TimelineViewModel.kt b/vector/src/main/java/im/vector/app/features/home/room/detail/TimelineViewModel.kt
index 77284edba0..755df16c1e 100644
--- a/vector/src/main/java/im/vector/app/features/home/room/detail/TimelineViewModel.kt
+++ b/vector/src/main/java/im/vector/app/features/home/room/detail/TimelineViewModel.kt
@@ -1111,9 +1111,13 @@ class TimelineViewModel @AssistedInject constructor(
             computeUnreadState(timelineEvents, roomSummary)
         }
                 // We don't want live update of unread so we skip when we already had a HasUnread or HasNoUnread
+                // However, we want to update an existing HasUnread, if the readMarkerId hasn't changed,
+                // as we might be loading new events to fill gaps in the timeline.
                 .distinctUntilChanged { previous, current ->
                     when {
                         previous is UnreadState.Unknown || previous is UnreadState.ReadMarkerNotLoaded -> false
+                        previous is UnreadState.HasUnread && current is UnreadState.HasUnread &&
+                                previous.readMarkerId == current.readMarkerId                          -> false
                         current is UnreadState.HasUnread || current is UnreadState.HasNoUnread         -> true
                         else                                                                           -> false
                     }
@@ -1132,12 +1136,17 @@ class TimelineViewModel @AssistedInject constructor(
                 } else {
                     UnreadState.Unknown
                 }
+        // If the read marker is at the bottom-most event, this doesn't mean we read all, in case we just haven't loaded more events.
+        // Avoid incorrectly returning HasNoUnread in this case.
+        if (firstDisplayableEventIndex == 0 && timeline.hasMoreToLoad(Timeline.Direction.FORWARDS)) {
+            return UnreadState.Unknown
+        }
         for (i in (firstDisplayableEventIndex - 1) downTo 0) {
             val timelineEvent = events.getOrNull(i) ?: return UnreadState.Unknown
             val eventId = timelineEvent.root.eventId ?: return UnreadState.Unknown
             val isFromMe = timelineEvent.root.senderId == session.myUserId
             if (!isFromMe) {
-                return UnreadState.HasUnread(eventId)
+                return UnreadState.HasUnread(eventId, readMarkerIdSnapshot)
             }
         }
         return UnreadState.HasNoUnread