Hi, thanks again for the advice. I did try regenerating the thumbnails, but still had the same issue.
After many days, I believe I have figured out that the image quality doesn’t have to do with wordpress, but rather with Chrome. I have been using the chrome browser and finally tried using safari and firefox. Images on my site look sharper in both these browsers and lose sharpness in Chrome. I am not sure if there is anything I can do about this, but at least I think I have figured out the cause.