I raised a ticket on Github for that. Certainly, the default is wrong if you purchased from Beamdog but activated the Steam key - there may be other cases, too.
I noticed that the new patch has deleted the hd art pack. I am not going to keep downloading and installing it every time there is an update.
Sounds like you may have installed it in the wrong place. It should be installed in Documents > Neverwinter Nights. That puts the files in the override subfolder, which isn’t changed by installing new releases.
It is possible to install it in the ovr subfolder of the game installation itself. In that case, it works, but will be removed by the next release.