Anyone have a noncustodial parent threaten or use COVID as a reason to reduce child support? Even if they are working ?

My ex is paying chid support and I’m our agreement, he should pay for half of our child’s swimming. The swimming pet month is $100. So his half would be $50. He claims he is not doing it because he already pays enough child support and if I want it I need to take him back to court, even if the judge already gave us an order that he had to. He also claims he is broke because of COVID cause he can’t do his under the table job so he won’t pay for our son to swim. I feel that if I take him to court his plan is to use COVID as a reason to reduce his support. That’s is what he is saying ...

He suppose to pay for a life insurance but he refuses to do that too.

Should I take him but to court or do you think it’s not worth it ?