Thank you! That's an interesting screenshot, hahah. The thing is that AGS always displays speech on top of everything else, including GUIs, objects, overlays, etc, so my guess is that ScummVM treats speech as just another overlay and the layer hierarchy got screwed up here for whatever reason. But it's just a wild guess!
And yes, it does work on Android, more or less. I was able to run it on my phone using the default Android launcher which comes as an optional download with every engine release, but unfortunately, when it came to the part where you have to enter the correct time for the clock, the keyboard would not pop up, making it impossible to finish the game. Apparently this was a known issue back then and I did not look further into it because I was just testing it out of curiosity and had no intention of launching an Android version, so I'm not sure what the state of things is right now in this regard.
Anyway, thanks for your kind words and glad you enjoyed it!