Kimmerz, I agree with Mirage...secretive is par for the course. As for the ow, she's calling the shots, therefore, he doesn't have to put much effort into the relationship or responsibilities right now.
As for the time of the phone calls, maybe it is when ow is at work and then again, maybe it's not. They tend to set up patterns during mlc and it's like clockwork when certain things are done. We may never know the answer to this one as each mlcer is different, but I do know that my xh had patterns of when he would call as well.
Keep your focus on you and your children. His behavior has no rhyme or reason for what he's doing.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.