Extreme server lag on mobile

[matthew35-dev]

What happened?

Device: iPhone 16 Pro Max iOS version: 18.6 Lichess app version: [Unknown] Network: Occurs on both Wi-Fi and 5G Description: Since around early August 2025, the Lichess iOS app has been extremely laggy during games, especially in bullet (1+0). Moves often take between 3–10 seconds to register on the server, and in extreme cases I lose up to 30 seconds on a single move, even though my network connection is stable (tested with other apps and speed tests). Steps to reproduce: 1. Open the Lichess app 2. Start a 1+0 bullet game 3. Play a few moves 4. Notice that after making a move, the timer continues to run for several seconds before the move is registered server-side. Expected behavior: Moves should be sent instantly, and the server clock should reflect my actual move time. Actual behavior: Even pre-moves often consume 3–10 seconds. In 1+0 bullet, I sometimes lose 30 seconds from a single move, leading to immediate losses on time. Workarounds tried: - Restarting phone - Force-closing and reopening the app - Reinstalling app - Disabling animations - Switching between Wi-Fi and 5G None of these resolved the issue. Additional info: Other real-time apps on my phone do not show this latency. The issue appears to have started after the latest iOS update and/or Lichess app update.

How can we reproduce the bug?

Steps to reproduce:**

1. Open the Lichess app
2. Start a 1+0 bullet game
3. Play a few moves
4. Notice that after making a move, the timer continues to run for several seconds before the move is registered server-side.

Expected behavior

Moves should be sent instantly, and the server clock should reflect my actual move time

Device

iPhone 16 pro max

Operating system

18.6

App version

8.0.0

Screenshots

No response

Additional context

Renders it impossible to play bullet on mobile. Mostly happens on 5g, with a strong connection