What type of Field are they in?
*Edit* --
I just looked at your breeding pairs fields and none of the pokemon are below Max Happiness. So Im confused about how we are going to help you if we can't see the same thing you are.
Aah, sorry. I had moved the pairing into fields that would raise the happiness back up as I was shocked by how fast their happiness had fallen. ;;-=-)a
But it had happened to my Murkrow pairing, Meowstic pairing, the Kingdra pairing [they're in 'My Sunshine's favorite Field', you can see that one of them is at full max but the other one is slowly having to build its happiness back up], and my Orthrus pairing.
All of these pairing were in those neutral fields and I was organizing them and realized that one pokemon of each of those pairing had lost a ton of happiness. I'm kind of scared to put them back into my "couple's retreat" fields and I'm now constantly checking on my other pairs in there to make sure that they're still at max happiness.
I had went to the bugs forums first but didn't see any thing about an issue like this and I wasn't too sure how I should even go about addressing this issue?