“Mom and Dad footed the college bill, made sacrifices to get that extra thing on their résumé, so they felt part of the process,” said Mr. Webb, who said that texting one’s parents was frequently the first reflex for the millennials in his charge after a run-in with a manager.

Brandi Britton, a recruiter with OfficeTeam, a division of the firm Robert Half, said she never saw or heard from parents when she entered the business nearly two decades ago but has increasingly felt their influence. She recalled a father calling her in the past two years in an attempt to get his son an accounting job. The father sent in his son’s résumé, scheduled the interview and, to her surprise, turned up with him in person. “He was shepherding that thing,” she said.

When OfficeTeam solicited employers’ helicopter-parenting stories in a 2016 survey, they found this was not unheard-of. One told of a job candidate who piped his mother into an interview via Skype, while another recalled a mother asking if she could sit for an interview in place of her child, who had a scheduling conflict. A third mother interrupted in the middle of an interview to ask if she could observe.

While such parents, like LaVar Ball, may be outliers, and most millennials are perfectly capable of negotiating their own way in the workplace, some organizations genuinely appear to be struggling with a scourge of parental meddling. In her book “How to Raise an Adult,” the former Stanford freshmen dean Julie Lythcott-Haims reports that officials at Teach for America have been mystified in recent years by the volume of parents who intervene on behalf of their adult children, whom the group employs as teachers.

A Teach for America administrator told Ms. Lythcott-Haims that parents had called him with complaints about such issues as their child’s being disciplined by a principal or having a run-in with a fellow teacher, as though the adult child were still a student. (Teach for America did not respond to a request for comment.)