Excluded Wi-Fi Networks functionality

iPhone 12; iOA 14.3; NextDNS version 2.0(28)

Should I expect the Exclude Wi-Fi Networks function to work? In my hands it does not. Have added 3 excluded Wi-Fi network names and the iOS application rarely transitions accurately between excluded wi-fi, included wi-fi, and cellular. Manual setting frequently required.

Are there detailed instructions for use somewhere that I've missed (e.g. requirements for network name format?) Apologies if I've missed something. I have searched and read what I could find.