No it’s not a new default feature, it’s been like that since the beginning which makes me think that maybe you are connecting to a desktop with a user account which is NOT the owner of the desktop you want to connect to. The default behaviour, as explained here: https://www.nomachine.com/AR04K00663, is when connecting to the remote desktop of a NoMachine host (server), the server asks for authorization to the remote desktop owner when this owner is different from the user who is requesting to connect. The connecting user must have a system account on the remote machine.
If you need to connect automatically to the remote desktop you have 2 options:
1) Run the connection as the same user who is logged-in to the remote desktop. If the connecting user is also the desktop owner, no authorization is necessary.
2) Configure the server on the remote machine to accept connection requests without asking for desktop owner’s authorization.
If you can confirm that you are doing exactly as stated in option 1) then we need more information:
i) what version of NoMachine on the server and connecting client
ii) what NoMachine product is installed on the server
iii) what OS is on the server