Chat shows blank boxes

- Copilot Chat Extension Version: v0.61.0
- VS Code Version: v1.133.0
- OS Version: WSL Ubuntu
- Feature (e.g. agent/edit/ask mode): Orchestrator Agent
- Selected model (e.g. GPT 4.1, Claude 3.7 Sonnet): Claude Opus 5
- Logs:

Steps to Reproduce:

I only see this in the Session view within a multi-agent orchestration. Whenever the Orchestrator invokes one or more subagents, I see the empty boxes as shown in the screen snip. The number of boxes varies, sometimes I've seen as many as 14 empty boxes.

I've tried copying, inserting the contents, in case it was present but not visible. I determined the boxes contained no content.