LRC does not remember import folder

In which case you need to consider what @JohanElzenga suggested and create an import preset which includes the destination folder. LrC will typically remember the last-used destination folder, but problems can arise if the last-used destination is on an external drive which is not online when you next start an import.

Then either save your settings as an import preset, or reset the preferences to see if that solves the problem: 

https://www.lightroomqueen.com/how-do-i-reset-lightrooms-preferences/

Is Q:\Photographs the destination folder where Lightroom copies the images, or do you place the images (not using Lightroom) there first and then import them (using 'Add', not 'Copy')? Like @Jim Wilde said, Lightroom has never remembered the source folder, but it should remember the destination folder. You can also save the destination folder (and all other import settings of the right panel) in an import preset. You do this at the bottom center of the dialog.

AFAIK, LrC has never "remembered" the previous import source when importing from anything other than a camera memory card. What you can do, however, is use the "recent sources" list which you obtain by clicking on "Select a Source" at the top of the left-hand panel of the Import dialog. That will show all recent import sources, so if you are using the same source each time it should appear at the top of the list.