Sorry you are having such a difficult time.
We are seeing more underwriters kicking back appraisals than ever before. In the past couple of months this has happened with several transactions I was involved in.
3 solutions that worked for my clients recently;
See if the underwriter will accept the appraisal with more comparable sales in the appraisal.
If not, check with the lender and see if the underwriter would be willing to accept the price with a second appraisal. This has helped me twice now in the past few months.
Finally if you are going through a bank, you may have to switch to a mortgage broker who may have more lenders to choose from. Then unfortunately find another loan program that will meet your guidelines.
Make sure that your agent looks at your loan commitment deadlines and follows up with an addendum to adjust the date if needed and the seller is agreeable.
What area of North Carolina are you in, Pat? I wish you luck.