I’m using an M-Audio Keystation88 with Cubase 13. For some reason, if I’m not pressing the sustain pedal, it’s like it’s always on, however, as soon as I press it, it shuts off the sustain. This has happened once before on another computer. After talking to tech guys in music stores and lots of probing chatGPT for solutions, the only answer was doing a complete reinstall. It’s not the switch on the pedal, which seems to be everyone’s first answer, too. Hoping someone can tell me a quick fix. Thank you.
Have you tried ensuring the pedal is connected before you power up the keyboard or after? Most keyboards self correct at that point..
In some apps and for some keyboards, when you start the app with the sustain pedal pressed, it inverts the sustain function (so sustain occurs when the pedal is pressed). If you start the app with the sustain pedal pressed, it inverts the sustain function of the pedal (sustain is applied when the pedal is not pressed). Something to try anyway.
Cheer Bigears 
Soz, I messed that up. Start app with pedal pressed, sustain is applied when pedal is not pressed. Start app with pedal not pressed, sustain is applied when pedal is pressed. Or vice versa maybe? … ! LOL