diff --git a/src/components/common/comment-mention-composer.tsx b/src/components/common/comment-mention-composer.tsx
index 63c84f22..140753b0 100644
--- a/src/components/common/comment-mention-composer.tsx
+++ b/src/components/common/comment-mention-composer.tsx
@@ -25,6 +25,41 @@ type CommentMentionComposerProps = {
   onSubmit?: () => void;
 };
 
+type MentionCandidateMenuProps = {
+  open: boolean;
+  anchorEl: HTMLElement | null;
+  candidates: MentionLookup[];
+  highlightIndex: number;
+  onSelect: (user: MentionLookup) => void;
+};
+
+function MentionCandidateMenu({
+  open,
+  anchorEl,
+  candidates,
+  highlightIndex,
+  onSelect,
+}: MentionCandidateMenuProps) {
+  return (
+    <Popper open={open} anchorEl={anchorEl} placement="bottom-start" className="z-50">
+      <Paper elevation={4} className="mt-1 max-h-48 overflow-y-auto">
+        <List dense disablePadding>
+          {candidates.map((candidate, index) => (
+            <ListItemButton
+              key={String(candidate.id)}
+              selected={index === highlightIndex}
+              onMouseDown={(event) => event.preventDefault()}
+              onClick={() => onSelect(candidate)}
+            >
+              @{candidate.name}
+            </ListItemButton>
+          ))}
+        </List>
+      </Paper>
+    </Popper>
+  );
+}
+
 export function CommentMentionComposer({
   value,
   onChange,
@@ -35,8 +70,6 @@ export function CommentMentionComposer({
   onSubmit,
 }: CommentMentionComposerProps) {
   const inputRef = useRef<HTMLTextAreaElement | HTMLInputElement>(null);
-  const valueRef = useRef(value);
-  valueRef.current = value;
   const [anchorEl, setAnchorEl] = useState<HTMLElement | null>(null);
   const [cursor, setCursor] = useState(0);
   const [menuOpen, setMenuOpen] = useState(false);
@@ -55,22 +88,23 @@ export function CommentMentionComposer({
     setHighlightIndex(0);
   }, [activeQuery?.query, activeQuery?.start]);
 
-  const syncCursor = useCallback(() => {
+  const syncCursor = useCallback((textOverride?: string) => {
     const element = inputRef.current;
     if (!element) {
       return;
     }
 
-    const currentValue = valueRef.current;
-    const nextCursor = element.selectionStart ?? currentValue.length;
+    const text = textOverride ?? element.value;
+    const nextCursor = element.selectionStart ?? text.length;
     setCursor(nextCursor);
-    setMenuOpen(Boolean(findActiveMentionQuery(currentValue, nextCursor)));
+    setMenuOpen(Boolean(findActiveMentionQuery(text, nextCursor)));
   }, []);
 
   const handleChange = (nextValue: string) => {
-    valueRef.current = nextValue;
     onChange(nextValue);
-    requestAnimationFrame(syncCursor);
+    requestAnimationFrame(() => {
+      syncCursor(nextValue);
+    });
   };
 
   const applyMention = useCallback(
@@ -150,30 +184,21 @@ export function CommentMentionComposer({
           fullWidth
           value={value}
           onChange={(event) => handleChange(event.target.value)}
-          onClick={syncCursor}
-          onKeyUp={syncCursor}
-          onSelect={syncCursor}
+          onClick={() => syncCursor()}
+          onKeyUp={() => syncCursor()}
+          onSelect={() => syncCursor()}
           onKeyDown={handleKeyDown}
           placeholder={placeholder}
           disabled={disabled}
         />
 
-        <Popper open={showMenu} anchorEl={anchorEl} placement="bottom-start" className="z-50">
-          <Paper elevation={4} className="mt-1 max-h-48 overflow-y-auto">
-            <List dense disablePadding>
-              {filteredCandidates.map((candidate, index) => (
-                <ListItemButton
-                  key={String(candidate.id)}
-                  selected={index === highlightIndex}
-                  onMouseDown={(event) => event.preventDefault()}
-                  onClick={() => applyMention(candidate)}
-                >
-                  @{candidate.name}
-                </ListItemButton>
-              ))}
-            </List>
-          </Paper>
-        </Popper>
+        <MentionCandidateMenu
+          open={showMenu}
+          anchorEl={anchorEl}
+          candidates={filteredCandidates}
+          highlightIndex={highlightIndex}
+          onSelect={applyMention}
+        />
       </Box>
     </ClickAwayListener>
   );
diff --git a/src/test/components/common/comment-mention-composer.test.tsx b/src/test/components/common/comment-mention-composer.test.tsx
new file mode 100644
index 00000000..a732af50
--- /dev/null
+++ b/src/test/components/common/comment-mention-composer.test.tsx
@@ -0,0 +1,28 @@
+import { screen, waitFor } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
+import { useState } from "react";
+import { describe, expect, it } from "vitest";
+
+import { CommentMentionComposer } from "@/components/common/comment-mention-composer";
+import { renderWithProviders } from "@/test/test-utils";
+
+const candidates = [{ id: "1", name: "Alice Dispatcher" }];
+
+function MentionComposerHarness() {
+  const [value, setValue] = useState("");
+
+  return <CommentMentionComposer value={value} onChange={setValue} candidates={candidates} />;
+}
+
+describe("CommentMentionComposer", () => {
+  it("keeps the suggestion menu visible after typing @", async () => {
+    const user = userEvent.setup();
+    renderWithProviders(<MentionComposerHarness />, { withAuth: false });
+
+    await user.type(screen.getByRole("textbox"), "@");
+
+    await waitFor(() => {
+      expect(screen.getByRole("button", { name: "@Alice Dispatcher" })).toBeVisible();
+    });
+  });
+});