diff --git a/news/1050.bugfix.rst b/news/1050.bugfix.rst
new file mode 100644
index 0000000000..8d60ee11b6
--- /dev/null
+++ b/news/1050.bugfix.rst
@@ -0,0 +1 @@
+Fix the live mode TUI showing only the first thread's allocations until merging was toggled, even though it starts in merged mode.
diff --git a/src/memray/reporters/tui.py b/src/memray/reporters/tui.py
index 96042e2579..a252b36c31 100644
--- a/src/memray/reporters/tui.py
+++ b/src/memray/reporters/tui.py
@@ -221,7 +221,7 @@ class AllocationTable(Widget):
     sort_column_id = reactive(default_sort_column_id)
     snapshot = reactive(_EMPTY_SNAPSHOT)
     current_thread = reactive(0)
-    merge_threads = reactive(False, init=False)
+    merge_threads = reactive(True, init=False)
 
     columns = [
         "Location",
diff --git a/tests/unit/test_tui_reporter.py b/tests/unit/test_tui_reporter.py
index efaeb9aa26..970352ce95 100644
--- a/tests/unit/test_tui_reporter.py
+++ b/tests/unit/test_tui_reporter.py
@@ -772,7 +772,7 @@ async def run_test():
 
             datatable = pilot.app.screen.query_one(DataTable)
 
-            for key in ("m", ">", "m", "<", "m", "<"):
+            for key in ("", "m", ">", "m", "<", "m", "<"):
                 await pilot.press(key)
                 functions.append(datatable.get_cell_at(Coordinate(0, 0)).plain)
                 labels = extract_label_text(app)
@@ -782,8 +782,8 @@ async def run_test():
     async_run(run_test())
 
     # THEN
-    order = [0, 1, 2, 2, 1, 0]
-    merged = [False, False, True, True, False, False]
+    order = [2, 0, 1, 2, 2, 1, 0]
+    merged = [True, False, False, True, True, False, False]
     assert functions == ["abc"[i] for i in order]
     assert tids == [
         "TID: *" if all else f"TID: {hex(i + 1)}" for i, all in zip(order, merged)