I have the same issue, feels like I've tried every setting Steam provides but none affect the mouse cursor showing every time I open the "home" menu (or play the BPM into video for that matter - which has a mouse cursor on top of it every time).

From what I can make of it this has been an issue since at least 2022 and I haven't seen any indication that it is being acknowledged or worked on either.

Friend, just try disabling Steam input in the controller settings and the mouse should not appear after that.

Cheers for the suggestion, unfortunately I've tried this thoroughly. It made sense to me that perhaps it was interpreting my peripherals as a mouse due to button mappings or like you say - Steam Input but alas.

I do have a multi monitor setup which I don't know if it matters but I perhaps other monitors somehow interferes with mouse exclusivity or visibility.

I have noticed while playing Marvel's Midnight Suns (not played any other game yet) that the perihperals change from Xbox Controller to mouse after some loading screens. Don't think it's related but you never know I suppose ^^