hi Harry
just checked my USBridge Sig and Roon Displays and found that three days ago auto reboot reverted to “Never” on its own :-/
I keep it set to “Daily” since… the day, years ago, I started using RoPieee
RoPieee 521 and 523 (both “stable”)
thanks for having a look 
I am not sure what might have happened (perhaps card related, given the number of likely writes?), but I’d be inclined to simply set the schedule again and see if that solves the problem.
As you likely know, RoPieee changed architecture earlier in the spring, so the Classic RoPieee that you are using has been deprecated. If you decide to upgrade, it will require a re-flash. More info on Harry’s website: RoPieee | Getting Started.