@mitu

Installing Stella was the trick.
Thank you for your help.
I know she's going to enjoy playing River Raid with the correct kind of controller.

@badviper Would you please advise what steps I need to take to make my retrolink usb controller work with n64?

Do I need to use lr-mupen64plus-next? I selected lr-mupen64*-something*

Do I need to modify /opt/retropie/configs/n64/InputAutoCfg.ini?

Do I need to reboot or only restart emulation station?

I don't understand the GUI option for selecting a Select button since my controller doesn't have one but games need that, right?

Any other steps?

Thank you!

Turns out it was underlying OS issue. For whatever reason, the update broke the gamecon driver for SNES controller input. After uninstalling the db9 and gamecon drivers, rebooting, reinstalling then rebooting, my pad now works as one would expect!

What cued me into it was while reviewing logs after an update failure I found a gamecon update failed message. Researched it and found this info at the link below.

https://retropie.org.uk/forum/topic/3875/solved-gamecon-installation-fails/10

@Efriim, really appreciate all your help and insight onto this issue. You helped direct me to look more into the software side and that's where it was.