Your story is very similar to mine. My ex only showed an interest in the kids for the first six months, the period between when I kicked him out and the divorce was final. They had been invisible before that. Once the papers were signed, he went MIA for three months, then went six months, until now he goes a year to eighteen months between contacting us.
At the modification hearing, when I took him back to court for more child support since he was not helping with time or expenses at all, he claimed I wasn't letting him see the kids. I knew he was going to do that and had a spreadsheet with each visit logged in at what location (99% my house, where'd he'd come sit on the couch and doze during his "visitation") and five statements from friends and family to confirm the spreadsheet was accurate. I also had our phone records and bank statements to prove expenses related to the kids and that he didn't call or text them.
The judge nailed him. Told him he didn't have anymore scheduled visitation, but that it was whatever was convenient for me from then on.
We get an email from him once a year or so, completely passive aggressive and a testament to just how much he loves to put on the "tortured soul" bit, while STILL making it all about him. A small excerpt of the one we got this past week:
Hello my children,
I feel like my using that pronoun for all of you right now is not received with a lot, if any, agreement from some or all of you. I do not have any other understanding from our recent interactions. This is how it should be, in my opinion, because I have demonstrated by my actions that I don’t care. I am under no delusions otherwise. I am deeply sorry and regretful that my actions, as interpreted by me, and a vast many others who have a vested interest in both my own and your well beings agree I have failed to show you what you mean to me and how I feel about you. These same people/relatives/friends also are vastly disappointed in me for letting my non-actions continue this long. Many of them relayed this message to me vehemently so. I know I haven’t been around with any kind of consistency for years. I know I haven’t communicated with you in any way that was beneficial. I know I haven’t done anything to show you I am interested in who you are, where you are going, or why you are going there. I have barely appeared in person enough lately for you to remember what I look like. I haven’t sent any birthday cards, Christmas presents, graduation cards, etc. for a couple of years. The presents I said were on the way that never arrived. At least in my memory that is the case.
We get a carbon copy of the same statements every time. Nothing changes, of course. This is just a recurrent self affirmation he does to polish up his self image. There's always some mention of demanding his visitation or time with the kids, even though he has none. There's always some veiled threat (if the contact is made during the spans he's employed and the state has garnished his wages) that his present job is a traumatic environment and he knows if he just took time to find himself, he'd be so much happier.
There's always some "subtle" fishing for information about me or if I regret ending the marriage yet.
My kids' response? "FTG." I tried to cushion it all for them, but they were the ones who told me to stop, that it was futile. They knew what/who he was way before I was ready for them to, but he kinda gave them no choice.
Hugs, dmari. When people only relate to people on a level of "what are they doing for ME/what am I getting out of it" relationships are disposable. To lots of men, this even means their kids, damning as that is.