Are you always creating a new connection file? In that case it would always show windows for “remote audio alert message” and “remote display resize message”. You can check “Don’t show this message again” and it won’t show anymore in this connection file.
There is also method to configure every host which you want to connect. Edit as administrator server.cfg and uncomment and change following key to this:
ClientMenuConfiguration input,display,display-mode,display-settings,connection,devices,devices-disk,devices-printer,devices-usb,devices-network,devices-smartcard,audio,audio-settings,mic,mic-settings,recording
(point 2 in https://www.nomachine.com/AR11O00951).
We also recommend to update NoMachine to newest version.