Sync to manual tempo control becomes locked

Hi all, 

Has anyone else observed that going from Sync to manual tempo control results in the tempo control getting stuck on the sync tempo BPM? In other words, turning off sync it appears to become stuck on the sync tempo unless you pitch right to the bottom or the top to  kick it out of the sync tempo and regain control again? Even nudging the tempo down or up does nothing even though sync is no longer on. I cannot work out why. 

I use sync sometimes to get non computer made tracks (e.g. disco with human drumming etc) in their BPM match but then move to manual control as you usually need to tweak the tempo here and there ,slow the platter down etc. 

Thanks!