This is really cool! Detective stories are usually stuck around the 1920s, but this one was an interesting blend of modern technology and ancient legend.
I really liked how you incorporated the timestamps into the mystery, I'd talk more about it, but I don't want to spoil anything lol.
I think it could be interesting if time progressed every time you sent a message, instead of in real time. That way, the amount of information you get depends on your ability to select the best questions instead of your reading speed. Also, I think the "dot dot dot" bubbles could add a lot to this, like you could see how long someone deliberates their answer.
This was really fun to solve, and I'm impressed with how developed the characters are and the volume of writing you made so quickly!