My guess is that you have the same issue if using the Smart Client. My guess is this - https://developer.milestonesys.com/s/article/View-and-stream-video-from-XProtect-Advanced-VMS-Recording-Servers-without-DNS-name-resolution
If this does not lead you to a solution, please test with the Smart Client.
If the Smart Client have same issue, please ask again in the Support Community.
If the Smart Client works fine and only the sample fails when tested in the same PC with the same user, please let us know.