@WhiteNoise @rigmarole Thank you for your help. I found the root cause.
Using a Retina display - Apple Support helped. As it turns out, “Open in Low Resolution” was selected in Get Info panel.
This is the solution from the support page:
- Quit the app.
- Open the Applications folder.
- Click the app once to select it, then choose Get Info from the File menu.
- From the Get Info window that opens, select the checkbox labeled ”Open in Low Resolution.”
- Close the Get Info window and open the app again.