Subject: [Bug Report] Flawed Virtual Scrolling Implementation in <ms-prompt-scrollbar> Causes Uncontrollable Jumping

Description:
The chat interface scrolling is fundamentally broken. A single scroll input (e.g., one mouse wheel tick) causes the page to jump uncontrollably across multiple conversation turns, making navigation impossible.

Root Cause Analysis:
The problem lies in the flawed interaction between the virtual scrolling mechanism and the custom scrollbar ().

  1. The application correctly uses virtual scrolling, rendering only a fraction of the conversation turns at a time.

  2. However, the custom scrollbar’s nodes are positioned based on the total number of turns in the entire conversation.

  3. This creates a massive disconnect: scroll events are incorrectly mapped to the large, virtual height of the whole conversation, instead of the small, physical height of the currently rendered content.

This incorrect mapping is why a small physical scroll results in a huge, disproportionate jump in the conversation history.

Verification:
Deleting the element via developer tools and restoring the native scrollbar completely fixes the issue, confirming this component is the source of the flawed logic.

Suggested Action:
The scroll event mapping logic needs to be corrected to account for the virtualized content. Alternatively, provide an option to disable this component and use native scrolling.


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