Create and use an Assistant thread using a Custom Assistant.
Refresh the page.
Access the Custom Assistant thread you just created and the profile will no longer be your custom assistant.
It seems to function correctly as long as the page is not refreshed, but if you access an older thread after closing or refreshing it will default to non-custom settings.
When accessing an existing thread, pre-select the settings that were last used on the thread, including Custom Assistants.
