Former Employer Collapsed. I Don't Know If They Paid The Insurance Company, And Now I Get A Retroactive Notice Saying The Plan Ended Earlier Than What Was Promised. What Do I Do?

EDIT: Here's the update: apparently they didn't pay (lmao, just incredible) but apparently were in touch to rectify the payment. Since payment was not received, the insurance company retroactively canceled coverage for the entire group until this is rectified, and the claims will re-process automatically when they get paid. Healthcare in this country sucks. OP below

Hi folks, currently navigating an insurance nightmare.

TL;DR former employer collapsed. Health insurance was promised through the end of March. I have printouts of company email correspondence with the insurance company rep saying it would end 3/31/24; I have a certification letter from the health insurance company sent earlier this month saying it ended 3/31/24; and I have correspondence from the former employer also saying it would end 3/31/24. I have to write that out 3 times because I feel insane.

I got a new letter in the mail yesterday from the health insurance company saying the end date, as of 4/24/24, was now 2/29/24. I went into my insurance company's portal and noticed that they processed claims through 3/7, and then everything after that was held up - and now all claims post-3/7 say that benefits were not active on those claims and we may owe the full amount. An expensive genetic test was serviced on 3/7 and it is saying benefits were not active, yet the doctor visit for that test on the -same- service date was successfully paid and processed and no note about benefits not being active for that claim.

All former employees used their healthcare coverage in March under the impression that it was still active, so this is a shock.

I am aware through conversations with folks from the HR department that the company was delinquent on their March payment. They had originally paid like 85% of the bill and not the remainder. They were sent a notice on the remaining amount, something like ~$2k, it was forwarded to the owners, and the delinquent notices (which would normally be sent to this employee) never happened again. It was assumed to be paid - surely they wouldn't cause hundreds of thousands of dollars of medical debt to their employees over a $2000 payment, right? (fucking hell, people)

Trying not to panic. What do I do? Contacted former employer and they are allegedly looking into it but I have zero faith in that particular group of people.

I am in Louisiana and the company was based here.

My questions:

1. Am I going to be responsible for the full entirety of these bills if it turns out they didn't pay the full amount of their bill to the insurance company? Again, the plan was paying for things through the first week of March, and just stopped after 3/7. As far as we all knew at the time, the plan was active when we used it, and as of the first week of April the insurance company apparently believed it too based on receiving that first certification letter.
2. I have not received any bills for all those claims between 3/7 and 3/31- yet. Should I wait to see if there is any resolution before paying any that show up? Which leads to question 3,
3. Is there any world where this turns out to be an error, the insurance company corrects the dates of coverage, and I don't owe the full amounts? With providers having to re-submit claims or something once corrected? We wouldn't have visited those doctors if we knew coverage would be ending. (Don't get an expensive genetic test when your employer is falling apart, I guess). Trying to stay grounded and understand what to expect.

If you need further clarification let me know. Hope that all makes sense.