Dell U2711 not recognized by Big Sur

Catalina was able to identify this monitor and provide all its possible resolution settings in the Displays preference applet. But Big Sur lists it as Unknown and give me a max of 1280x1024. I am on a brand-new M1 Air, connecting to the monitor's VGA port via a Cable Matters Thunderbolt->VGA adapter. The previous machine was an old Air running Catalina with a DisplayPort->VGA connection.

Checked Dell and it appears drivers aren't needed or offered. What should I do here? Thanks in advance.