Cubase Elements 9.5 - Issues with MIDI

Not sure if its Cubase Elements 9.5 (trial) or the Behringer interface UMC404HD
Have connected my Yamaha PSR s970 to the interface’s MIDI In/OUT
When I play with auto- accompaniment turned on, the sound that gets delivered is completely
distorted and messed up.

The relationship between the s970 and the computer looks complicated. https://www.yamaha.com.cn/uploads/file/20170925/Computer-related_Operations.pdf. There are . I don’t know the s970, but I’d guess the auto-accompaniment isn’t sent as MIDI over USB. It might be held in the s970’s internal memory, generated on the fly, or somehow encoded (such a a single midi note representing a chord – I wonder how .sty files work). Or it could be that you need the Yamaha Standard USB-MIDI driver. Or it could be a synchronization problem, if Cubase and the s970 are trying to sequence MIDI at the same time.