Newsflash: New Year’s Eve question, need help ASAP

My wife and I are selling our house in Jackson, MS area.We were supposed to close today, however it looks like we will NOT close till January 4th 2021. We were given an anonymous tip stating if it does close Today we would be responsible for $3,000 worth of next years taxes.I was also advised to move back in the house and start living there again.Please excuse my lack of clarity and knowledge on the subject matter. Thank you for any advice in advance.Also, what constitutes me living there. I know I need to sleep there , is there any thing else. All utilities are still on at the house.Thank you