Message list does not scroll to bottom when sending a custom emoji as the only content (Desktop app only, works in browser)

[bababuilmao-sketch]

Search before asking

• I had searched in the issues and found no similar issues.

Operating System

• macOS
• Windows
• Linux

Operating System Version

Windows 11

It happens on the web browser too?

No, it just happens on the Desktop app

Rocket.Chat Desktop App Version

4.17.1

Rocket.Chat Server Version

8.8.1

Describe the bug

Description

When sending a message that contains only a custom emoji and no text, the message
list does not scroll down to the new message. The behaviour is intermittent:
sometimes it scrolls on the 4th emoji sent in a row, sometimes on the 5th.

The same server, same user and same custom CSS work correctly in a normal browser,
so this appears to be specific to the desktop app rather than to the server version.

Actual behaviour

The list stays where it is and the new message is below the visible area.
Clicking the jump-to-bottom control works as expected.

What I already ruled out

• Plain text messages: always scroll correctly.
• Custom emoji followed by text in the same message: scrolls correctly.
  Only an emoji on its own is affected.
• GIFs sent through the Giphy integration: scroll correctly. These are rendered
  as attachments rather than inline, which may be relevant.
• Custom CSS: cleared completely, behaviour unchanged.
• Emoji size: tested with the default size, with a much larger size, and with
  .rcx-message__emoji--big set to exactly the same height as the inline variant.
  Behaviour unchanged in all three cases, so the height difference of the
  emoji-only rendering does not appear to be the cause.
• Same account, same server, same channel in a normal browser: works correctly.

Server setup information

• Version of Rocket.Chat Server: 8.8.1
• Deployment method: docker (docker compose)
• Number of running instances: 1
• DB replicaset oplog: enabled
• MongoDB version: 8.0.32
• Host OS: Windows, Docker Desktop
• Number of users: under 10

Client setup information

• Desktop app version: [HIER DEINE VERSION EINTRAGEN, siehe Help > About]
• Operating system: Windows
• Browser used for the working comparison: [HIER DEIN BROWSER UND VERSION EINTRAGEN]

Additional context

Rocket.Chat 8 migrated the main message list to a virtualized implementation
(PR #40105 in the main repository, using the Virtua library). Since the same
server behaves correctly in an up-to-date browser but not in the desktop app,
the bundled Chromium version in the app may be reporting resize events
differently than a current browser does.

How to Reproduce

Steps to reproduce

1. Upload an animated custom emoji (GIF) via Administration > Custom Emoji.
2. Open a channel in the desktop app and scroll to the bottom.
3. Send the custom emoji on its own, with no other text, several times in a row.
4. Observe that the list stops following the newest message after a few sends.

Describe your Expected behavior

Expected behaviour

The message list scrolls to the bottom after sending, as it does for text messages.

Anything else

No response

Are you willing to submit a code contribution?

• Yes, I am willing to submit a Pull Request!

[iamshravanijadhav]

Hi @bababuilmao-sketch , I’d like to work on this issue. I’ll look into the scrolling problem with custom emoji messages and try to find the cause and fix it. Thank you !