What is the quick command you are trying to construct? Ive noticed with some Bixby quick commands, depending what is on the screen when a command is executed has an impact if its done, not or a prompt appears.
I have a quick command that opens email app, checks for new messages, switches to all accounts, selects all messages and marks all as read. Then returns to the home screen. It took allot of trial and error to make it work.
Bixby always got stuck on the select all email. In a quick command it wanted to search for an email. But when executed separately it selected all mail. By changing the one command from "select all mail" to "email select all" it worked. But then I was able to do away with that command by simply skipping it using "Mark all email as read". Which replaced the need for selecting all.
Sorry for that long explanation. Its just an example how something simple can not work when stringing commands together. Sometimes you need to be specific and other times use the app name in the beginning of a command.