Pls help what can be done???

Ok so I'm new to the whole child support stuff and my child's dad has been getting his checks garnished from his primary job, well for the last 3 weeks payments stopped and wondering what's going on I called thinking it was because of the government shutdown but I was told he changed employers. He changed it to his second job that he barely works (once a week and often takes off from that job) I'm guessing so they won't be taking majority of his check from his primary job. I know it will add up now that I know his second job won't cover the full amount due but is there anything I can do to get it back to how it was? Like modify it or something?