The bug
When you use the command /title @a reset or /title @a clear and you have a title in the actionbar slot, it does not reset/clear it.
Code analysis
Code analysis by @unknown can be found in this comment.
Linked issues
Attachments
Comments 3
This issue still exists in Minecraft snapshot 23w07a.
Code analysis (Yarn mappings)
The InGameHud#clearTitle and InGameHud#setDefaultTitleFade methods are responsible for the client portion of clearing/resetting functionality.
The former method clears the InGameHud#title, InGameHud#subtitle, and InGameHud#titleRemainTicks fields, but not the corresponding InGameHud#overlayMessage and InGameHud#overlayRemaining fields used for action bar/overlay messages.
Since there are no fields for overlay timing (MC-106167), they are not reset by the latter method. The existing timing fields that are reset are not used for overlay timing.
The recommended fix would be to clear the InGameHud#overlayMessage and InGameHud#overlayRemaining fields in the former method. Timings would require the recommended fix for MC-106167.
I assume that this is intended. The actionbar is rather unrelated to titles. Times will not affect it and it is shown regardless of whether or not a title is currently visible (which is not the case for subtitles).
You can easily clear the actionbar by displaying an empty string: