The command you posted, the first command would run the Collection and only use the cli reporter (by default if one is not added to the command) but it would create a file for the run.
The second command would run the Collection with the cli and junit reporter and output the xml file to your specified location. Only the second newman run command creates a report.
Unsure what you’re trying to achieve here, was the expectation to see 2 different reports created for each newman run command?