Welcome Barry Boy,
I understand how frustrating it can be when Microsoft Store is not saving the installation folder you select, and downloads cannot proceed because the folder remains unselected.
Before we proceed, I would like to clarify a couple of things:
- Does this happen with all apps/games in Microsoft Store, or only a specific download?
- Is the folder you are selecting located directly on drive D:, or inside another folder with custom permissions?
I look forward to your reply so we can continue working together to address the issue.