I'm very new to home tanning and over the last two years I've tried my best to follow the great advice on this site and also the trubond instructions. At this point I've tanned fox, coyote, and bobcats with trubond products and had results that I was happy with for wallhangers, however I've noticed the leather side on my furs is starting to yellow, they used to be nice and white but over the last couple years are yellowing to varying degrees, especially the bobcats. Is this ok or did I do something wrong in my process? The hair isn't slipping and there is no noticeable smell, just the discoloration.

Could be oxidation from chemical salts left in the leather after tanning.
Tanned furs can deteriorate over time if not looked after.
Never store tanned fur in damp areas,Any salts inadvertently left in the skin will attract moisture out of the air (hygroscopic) where humidity is high like in a basement in summer.
Good fur garments are kept in cold storage over the summer,but that is not necessary for a wall hanger,just make sure if you store them in a basement to run a de humidifier in summer.

Thank you for the info! I do hang them in the basement where the humidity does occasionally get up there, generally it is around 55 percent. I will keep a closer eye on them to hopefully prevent any more deterioration.