Mine tried to do that too
Mine tried to do that too. Seems to be SOP. You got a lawyer? Mine went in ex parte (without the parties being present) and the judge put a fast stop to what TW (That Woman) was doing.
Assuming you have a court-ordered parenting/custody plan in place giving you visitation, your ex- is in contempt of court.
Get your lawyer on it and hang on … in the long run your kid will know you did.