When using the built-in Firefox AI sidebar and clicking the "Summarize page" button, I consistently get the error: "431 Request Header Fields Too Large" from chatgpt.com. Cookies were cleared multiple times Extensions (including AdGuard) were disabled The issue persists Previously, changing a privacy setting temporarily helped: switching from "block all cross-site cookies" to "block cross-site tracking cookies and isolate other cross-site cookies". After that, the feature started working. However, after restarting the browser today, the issue returned, and changing this setting no longer helps. I would also like to note that currently there is no way to disable or hide the "Summarize page" button, even though I did not need it initially. I tried to configure things so it would work properly, but was unable to do so. Steps to reproduce: Open any webpage Open the Firefox AI sidebar Click "Summarize page" Observe error 431 Expected behavior: Page summary should be generated successfully. Actual behavior: The request fails with HTTP 431 error.