Keyboard input lag on mobile phone

Hello all.

I’m making a small “musical” app that read keyboard strokes and plays back a sound. Everything is pretty much static, no animations or sprites moving around, except when the notes are played which triggers a glow effect around the note.
I have exported the app to HTML5 and on my laptop everything runs pretty smooth. The problem is the latency I get when I try to use the app on my mobile phone with an external keyboard. When using the same external keyboard on my laptop I didn’t have any latency. I have also limited the highest FPS to 30, just to keep things using as low CPU as possible.

Any ideas what I could try or change maybe? Should I just skip gdevelop and try to replicate the app using plain HTML and JS?

Thank you,
Stelios