Reported by @sullen furnace
Bug Report: The regenerate button disappears after using canvas
`Steps to Reproduce`
- Ask ChatGPT to use canvas
`Expected Result`
When exiting the full-screen window of canvas, the regenerate button should be available in every message, including previous ones
`Actual Result`
The regenerate button disappears and it's hard to regenerate responses or switch models
`Environment`
Web version (mobile, not sure if web PC is affected)