I would suspect that the problem is in the Casio keyboard.

The first thing I would do is try the MIDI file in a sequencer/DAW (Real Band would work just fine) and see if the tempo can be changed.

Then try other MIDI files in the Casio that are not made with the Casio and see if the tempo can be changed.

That would confirm or negate my suspicion and perhaps point to the problem.

Insights and incites by Notes


Bob "Notes" Norton smile Norton Music
https://www.nortonmusic.com

100% MIDI Super-Styles recorded by live, pro, studio musicians for a live groove
& Fake Disks for MIDI and/or RealTracks