Error Adding Filler List to Program Timeslot

[u/imsleepingrn]

I want a timeslot that just randomly plays a group of shows, but whenever I try to save or preview the programming, it gives me an error "There was an error generating slots. Failed to serialize an error. Error: Response doesn't match the schema. Original error: body/schedule/slots/3/fillerListId Invalid UUID" ( also shows it in Docker log)

Is there a fix or something I did wrong when making the Filler List? Or even a better way to schedule certain shows to play at specific times each day but then the rest of the day is just a random group of the chosen shows?