Display no signal when graphics driver loaded

Scratching my head for days on this this one. Have weird Wisecoco 1080p 7" display. Works fine via HDMI connected to a Windows 10 PC, and a Steam Deck with Steam OS via a usb-c to HDMI adapter, so I know the display is functional. It also works connected to this Mini PC while in the bios menu. The display says "no signal" as soon as the graphics driver loads before the login screen. When connected to a different monitor, I can plug this in as a secondary display, but it doesn't show up in KDE Display Configuration. While connected like this, it seems to keep trying to reconnect, with my main display freezing every few seconds. Seems like it's trying to negotiate a connection and failing. I noticed in kwinoutputconfig.json that the display appears to show up with a refresh rate of 60 hz, but I do notice when it works in other OSs it appears to be 61 hz. Any advice on getting this working? Maybe a way to force 61 hz?