I am not sure how far you’ve gone troubleshooting wise, but go to this thread and follow the instructions. May help: https://chiaforum.com/t/plot-detected-as-not-found-plots-after-plotting-finished/5249
I had the same issue about a week ago when I installed a NVMe into my main farming rig, and this worked for me. Took a little time, but I got all my plots to be recognized again.