I'm going to guess that the "other" channels are from Nimiq1 at 91W, only 2 degrees away. It is possible that you could pick up some of the powerful , circular polarity tp's from 91W with your linear lnbf, if your blindscan wasn't limited to 11700-12200.
What receiver are you using ? I'm guessing that the blindscan frequency range default extends right through the 11700-12900 range, which would not only probably pick up Nimiq1 for you, but also take a lot longer than necessary to scan Galaxy 28 . Two of my receivers, an IV200 and a BUZZ Plus, both have the "too large" blindscan frequency range. You'll want to see if you can limit the scan range to 11700-12200 on your blindscans, to avoid this problem. I doubt anyone will re-write the firmware to make it easy.
