Help: Question about Sterling HS

I recently purchased a ca. 2000 4 string EBMM Sterling HS. I have read about low volume in positions 2 and 5, and although that is somewhat true, I find a significant drop in treble response in those positions. Like a wet blanket. Not like anything I hear in various on-line demo videos. Is this normal?
Also, I found that I get different tones in “half positions” on the selector, particularly between 1 and 2 and between 4 and 5. An increase in bass response. Have not seen any discussion of this. Has any one else noticed this? Thanks!