monbosapin
Thank you! Now I understand what @divyanshu was talking about. I'd never turned that setting ON when I was using Budgie (it defaults to OFF), and had no idea how that feature was used. I did turn it on just now, and I better understand the original issue.
Apparently you have the answer for him. If it's a question of his keyboard shortcuts affecting all applications in all workspaces instead of just the current workspace, apparently he might only need to turn on the setting you described. That appears to be what it's used for.
If turning on this setting doesn't solve his problem, would you please try to help him further? It's a problem I don't have with a feature I've never used -- that's why I was having a hard time understanding.