Two months ago, I trained a segmentation network using Fastai ver.1.0.51, and I got excellent results. However, yesterday I updated Fastai to version 1.0.59, I tried segmenting the same image, and the results were terrible. So, I downgraded Fastai, and the results are back to normal.
It is the same model I had performing worse!!. The thing that saved me is I used Floydhub website during the training stage. I checked the results in Floydhub and they were as I left them two months ago. I downloaded the trained model from the site on my PC and again I got bad results. Therefore, I knew that the problem is not in the trained model, the problem is either in the installed fastai or some drivers. Luckily, I started with downgrading Fastai to the same version I used in floydhub and it solved the issue.