NC: Ex has violated Consent Agreement and has some other troubling issues - how to proceed?

Hello, I hope this post is in line with the guidelines.

TL:DR: Ex introduced kid to boyfriend before giving notice to me. Boyfriend is affair partner, is on recording doing drugs (pot) with ex. Ex also forgets to give kids their medicine frequently, which includes anti-anxiety and a psychotropic). Is this anything to pursue in family court?

My ex-wife and I both married, divorced, and live in NC. We separated in early 2024, came up with a consent agreement in mid 24 amicably, and legally divorced in early 2025, so we have been legally divorced for more than a year now. We have two minor children, 17 and 11. The consent agreement was pretty boiler-plate. We have 50/50 custody.

"Neither party shall have overnight guests of the opposite sex not related by blood or marriage while the minor children are in their custody until such time the party and their significant  other have been in a committed dating relationship for a period of six (6) consecutive months following the entry of a judgment of absolute divorce. The parties shall not introduce their significant other to the minor children until such time the party and their significant other have been in a committed dating relationship for a period of three (3) consecutive months following the entry of an absolute divorce judgment and must give the other party advance notice of their intent to introduce the children to their significant other."

She introduced her boyfriend to our youngest last weekend as her boyfriend, along with his kids from a previous marriage. I only heard about it from the kids, not a peep from her.

Here is some more concerns that may or may not be relevant: her boyfriend is her affair partner, which is why our marriage ended. She is a (supposedly) recovering addict, was in recovery for 4 months in 2018 for opioids following a surgery, relapsed in 2019 briefly, and then relapsed with just pot and alcohol in 2023. From during her affair, I have record of text messages between her and the boyfriend talking about getting high together, and possibly of him dealing weed vape pens. My lawyer had told me that judges generally do not care about affairs and pot when dealing with child custody.

The other concerning thing that may be applied to family law: She falls short as a parent in some regular human ways, like getting our youngest to school late sometimes. But she will forget to give both kids their medicine around once per week (anti-anxiety and ADHD medicine for one, and ADHD meds and a pha-2A adrenergic agonist [psychotropic] for the youngest). I handle all the medicine and give her some a bit at a time per our divorce agreement (I insisted on this in our divorce agreement). I give her 2 weeks of medicine for the kids at a time. She admitted last week by text message that she had missed their medicine 7 out of 14 days from the last go-round. During that time, our youngest, who takes the psychotropic, had an incident in school where his teacher had to call me for misbehavior, he said that "intrusive thoughts" made him misbehave. He has a history of misbehaviors based on an ASD diagnosis at 4 years old and had steadily improved until last year.

Anyways, if you've read this far, thank you. I'm without a compass here. My ex is not a terrible mom, but the little instances of negligence build up. I'm afraid if I confront her harshly on the medicine, she'll just lie and keep the leftovers. I do think the kids would be better off with me full time and show a preference for me (I can safely say I've been 80-90% of the parenting since the oldest turned 3 because of mom's work schedule, addition period, and recovery work). I suppose my direct question is would a judge factor any of this in to a request to alter custody? We had both freely agreed to 50-50. Otherwise, do I have any other recourse?

Thanks for any guidance!