PSR S775

[Mr. Gary]

Hello,  advice appreciated.
In a few articles I noticed the reference to some files being 'keyboard specific.' for example  the corrected music files .I have the PSR S775 , there is no reference to that model for the corrected titles,  can I use an alternative such as the 950?

When I select arpeggio with strings on style, the right hand on some Melody notes the arpeggio doesn't work, only a single note is played, any ideas?
B regards

Gary