Received a demand letter almost a year ago, now I’m being threatened suit

Location: Georgia

My husband and I sold a new construction house 2 years ago. (We didn’t want to sell the house, it was my dream home, but we couldn’t afford to keep it) The homeowner claims that we have lied on the disclosure form. Last year, we received a demand letter to the tune of $20,000. The homeowner claims that the basement has flooding problems. We responded promptly, meeting with his attorney and providing numerous photos of the property condition at the time of sale and photos of the property’s improvements after the time of sale (homeowner added a detached garage and part of the demand letter said that he was having flooding on his new concrete pad and in the garage). We did not hear anything further from his attorney and assumed that they moved on.

Now— almost a year later— the homeowner has texted my husband directly to threaten a law suit against us if we don’t pay him $5,000 directly.

While I don’t believe he is being represented by an attorney at this point— because texting us directly, and in this manner, is wildly inappropriate, I’m curious on the legality of following through with a suit so long after the demand letter meeting. It seems improper, to me, to receive a second demand letter regarding the same issue.

What are some educated thoughts on this issue?