[Windows] Cannot reply to an existing ChatGPT conversation unless I branch it

What issue are you seeing?

In the ChatGPT app on Windows, I can open and read an existing conversation, but I cannot continue replying in that chat normally.

The only workaround I have found is to create/continue from a branch of the conversation. After branching, I can reply again, but the original chat remains effectively non-replyable.

This means I have to keep branching a conversation just to continue using it.

Steps to reproduce

1. Open the ChatGPT desktop app on Windows.
2. Open an existing conversation.
3. Try to send another message in the same conversation.
4. The normal reply flow is unavailable / does not let me continue the conversation.
5. Branch the conversation from an earlier message.
6. In the branched conversation, replying works again.
7. Repeat: when the issue occurs, another branch is required to keep replying.

Expected behavior

I should be able to keep replying in the same conversation without creating a branch.

Actual behavior

I cannot continue replying in the existing chat and have to branch the conversation to regain the ability to reply.

Platform

• ChatGPT desktop app
• Windows
• App version: unknown

Additional information

A screenshot shows the affected conversation and that I had to use the branch/“Continued from …” flow to continue replying.

I can provide the screenshot and app version/logs if needed.

Reproduce this in the Windows desktop app by opening an existing conversation and testing normal reply versus the branch flow; record the app version and logs if available. Done means the original conversation accepts a new reply without requiring a branch, with the behavior verified against the listed steps.