DavidR
2
I’m not at my desktop with 17.2.2288, so I don’t know for sure if your settings are the same. This win10 laptop still has 12.3.2280 and that has a Removable Media scan, and that has All Removable Media as the default option.
It would appear that external hard drive isn’t treated as removable media. But this F.A.Q. contradicts that https://www.avast.com/faq.php?article=AVKB178.
The difference on directory scan is you are actually giving a drive letter to be scanned, where the Removable Media scan has to determine what drives are media drives.
EDIT: I have reported this to try and draw attention to this issue.