Text rendering shows duplicated / stale content

Description

Description
The text section of the chat output is very unreliable. Content frequently appears duplicated - blocks of text repeat or overlap, and occasionally stale/older text is shown in place of the current response. This makes following a conversation verv difficult.
Steps to reproduce

1. Open a conversation and send a message (even a short one). 2. Watch the response render live while the assistant is typing. 3. The duplicated overlapping text appears already during typing - no scrolling or interaction needed.
   Expected behavior
   Each message renders once, in order, with no duplicates or overlapping text.

Actual behavior Text is duplicated overlapping / stale text shown instead of the latest message, already while the response is being generated.
Environment

• OpenCode version: 1.18.15 ⁃ Interface: TUI OS: Linux - Home Assistant OS ( raspberrypi4-64, kernel 6.18.34- haos-raspi) Terminal emulator: ttyd (web terminal, xterm.is), via tmux 3. 5a ( TERM=tmux-256color) Provider/model: opencode/big- pickle
  Additional context
  Happens with short responses too, so it is not size-related. Screenshot/video: attach if

Plugins

No response

OpenCode version

No response

Steps to reproduce

1 .Open a conversation and send a message (even a
short one).
2. Watch the response render live while the assistant is typing.
3. The duplicated overlapping text appears already during typing - no scrolling or interaction needed.

Screenshot and/or share link

https://www.dropbox.com/scl/fi/0v5a5b4z1nbdsywcyhd2s/Screenshot_20260810_020730_Home-Assistant.jpg?rlkey=cm962jzjqet3laul5gepnxi60&st=9onlvof4&dl=0

Operating System

Android Home Assistant

Terminal

No response