OOP maximum has been satisfied — but insurance says I still owe copays — can that possibly be correct? (HDHP in Louisiana)

I have a family plan, HDHP, in Louisiana. My son is in ABA therapy, 2-3 times per week. Therapy is considered “Tier 1” / EPO under my plan (i.e., this is not an “out of network” issue). After my son satisfied his individual deductible ($3,000), his therapy costs became 100% covered, but with a $50 copay per session. He recently satisfied his individual OOP max ($4800). We have not satisfied the family OOP max, and probably will not.

Despite my son satisfying his OOP max, insurance has continued to charge us $50 copays for his therapy. When I called insurance to inquire, they told me that hitting the OOP max has no effect whatsoever on the copays. As in, there is literally no maximum to the amount of copays that we might pay in a given year. That makes no sense to me! I thought the whole point of an out of pocket max was that…it was the maximum you would have to pay out of your pocket? We have not satisfied the family OOP max, but that does not seem to be the issue.

On the phone, insurance kept telling me: “only the deductible and coinsurance amounts accrue toward the OOP max — copays do not accrue toward the OOP max.” I don’t understand that at all. I kept trying to explain “I have already satisfied the OOP max [they do not dispute this], so it’s not an issue of whether copays count toward the OOP max, it’s an issue of whether hitting the OOP max relieves me of paying the copays.” The rep did not seem to understand/appreciate a distinction there — I’m not sure if the misunderstanding is on their end or on my end.

I am still trying to get a copy of the full policy / schedule of benefits — it’s not available online, and my insurer is dragging their feet providing it to me. All I have currently is a “summary of benefits” from the website, which does not contain everything. Here’s what the summary of benefits says — these are general comments about copays / OOP max, not specific to ABA therapy (I assume more specifics are provided in the full schedule of benefits) —

“After the Per Member within a Family Out-of-Pocket Amount is met, the Plan will pay one hundred percent (100%) of the Allowable charge for Network Covered Services, for that family member, for the remainder of the Benefit Period.

The Plan Participant must pay a Copayment each time applicable Covered Services are rendered, until the Plan Participant meets his Out-of-Pocket Amount.”

My questions:

Is this actually a thing? It seems to render the OOP max meaningless, unless I am missing something.

Is there something in particular I should be looking for in the schedule of benefits to clarify this issue?

Any particular strategy for appealing this issue?

Thank you so much.