Is this a QLE and does coverage get retro activated?

I went on maternity leave and was due 12/24/24, baby was late and came 1/1/25. Apparently my maternity leave made me ineligible for insurance on the last day of the month that my maternity leave started. So my insurance termed on 12/31/24, without notice and no offer of COBRA.

Can my husband add me to his as a QLE and have it backdated? The hospital has already billed me as uninsured for my labor and birth so I have to figure this out immediately…. I spoke to my employer and they are trying to get my insurance reinstated retroactively but have no idea how long it’ll take or if it’ll actually get done, we have already wasted a week on this so I’ve gotta figure this out asap.