Was able to have three people on different Windows 10 machines duplicate and verified issue.
Also tried various mod loaders (FTB, Curse Forge, and Prism) all new clean installs.

Narrator does not narrate chat even though when switching to "Narrate Chat" it does narrate mode changes.
It will NOT actually narrate just the chat.
When set to "Narrate All" it will then narrate the chat. Switch back to only Narrate Chat and it does not narrate the chat even though it narrates "Narrator Narrates Chat".