Extra questionmark appears wrapping to new line if the message ends with an emote that overflows the chatbox width

[Aleksas Legačinskas]

Seems like it might be some weird word wrapping going on that introduces additional byte(s)?
Video: https://streamable.com/k2vglc

Message: "so you could run NA cups without screwing everyone over LUL"
To repro any message ending in an emote works.