Action too high but fret buzz from on all frets from 7th to 23rd

[colin100]

I usually set up my own basses and can nearly always get them just the way I like them but I have a Musicman Bongo 5 and have been trying to set it up nicely. Recently I made some adjustments too the saddles and truss rod as the action was too high for me and also had fret buzz on all strings from the 7th fret onwards. I haven’t had much success and have settled for a compromise of action that is too high and a little fret buzz on these frets. 
 

Any suggestions to remedy this are more than welcome. 
 

Thanks

 

Colin