I'm running Subeta on Google Chrome on Windows 10. When midnight rolled around today, Shinwa's quest was still marked "Completed!" on the Quests sidebar widget. When I click through to the Temple of Shinwa, I reach the typical screen where she says she needs her beauty rest and to check in tomorrow.

FYI I posted it here :) https://subeta.net/forums.php/read/8581/Did-something-fail-to-reset-Post-here

If Shinwa resets for you later but not for other users, it's the 24 hour timer which runs parallel to the midnight timer.