No blue tooth advanced settings on Mac mini Monteray

My Mac Mini won't stay in sleep mode. I have to turn my computer off if I want to leave it for any length of time. I'm wondering if it has something to do with the fact I'm using a bluetooth keyboard. I notice others have asked the question and the suggestion is to click the advanced settings in bluetooth preferences and uncheck a box. I don't have advanced settings in bluetooth. How do I get these back? Or how else can I stop my Mac not staying in sleep mode, please?

Thank you