Sudden 30 day hold?

I feel like I know what caused it but also not sure. I have been selling at the same consistency I always have and items around the same amount of money. However, I have now gotten sudden 30 day holds the second the item is marked delivered.

For example, it will say “on hold awaiting delivery, your funds are available within 2 days after confirmed”. As soon as it’s marked delivered it switches to “available within 30 days”. I recently had a new buyer account do a chargeback for unauthorized purchase after it was delivered (with signature). I received notifications from eBay saying they would cover me etc. Everything was fine and then boom this happens.

I now have thousands of dollars in sales on hold for 30 days and not sure if there is any way to expedite this as it seems really strange that the second it’s delivered it changes to this. Anyone have experience?