Post Divorce Debt

My marriage ended in 2020 and divorce was finalized May 2024. We had a credit card with a little over 15,000 on it that was in both our names. Well he understood banking better then me, I had the card and he was a user of some sort. So needless to say it didn't affect his credit or anything so he stopped paying the credit card bill. I was at the time literally borrowing money to get my electricity turned back on as well as numerous other issues. So I could not pay the bills. Last date the debt was paid was July 2022 and it shows in my report as a closed credit card account and with payment status as In Collections/Charge Off and still lists the original bank as the contact. Here is my questions: Though I can see the payments marked derogatory by the bank, not a single one is actually on my credit report, only the late payments. If I go under number of derogatory payments its marked as 0. I also have 0 marked for accounts in collections. Will I make it worse by trying to pay this debt off now? I don't know how one place lists collections but nothing is fully reported to the agencies. I have received phone calls that show are from collections but I have not spoken to or even picked up a single call. I have also received letters from collections agencies offering deals and trying to collect the debt. Again I never acknowledged or signed for anything. So who actually has my debt, the bank or a collections agency? Do I keep ignoring this in hopes it just stays this minor on my credit report until it falls off? I'm currently in 700s for credit Do I answer a call from collections and ask for proof of debt? Its been years of ignoring and no collections agency has reported to credit accounts. Do I call my bank directly and attempt to handle the debt through them?

I've reviewed how to talk to collection agencies. But a lot of information about credit and who actually owns the debt is confusing me. I hope this post made sense.