White balance question

Himilou Posts: 5 Just Starting Out
I am making my through the basic tutorials and applying what I've picked up to some footage I've taken ( outdoor, evening ).
I am using the white balance effect and its very cool that HitFilm groups similar clips together and applies the correction across the group of clips.
In one particular group of clips at the tail end of the final clip in that group ( not at a cut point ) the white balance effect just completely drops out, and the video looks like no white balance is applied. Not sure why. Should I just trim this particular clip to remove that portion?

Also Is there any way to do something like a crossfade for white balance between clip groups that are selected by HitFilm? For each group I am trying to pick a white object to base the correction on but since this footage is shot while riding my bicycle I can only get close.

Thanks All!