Adjust the days of supply on the part record… if its zero it will create a new PO suggestion every time a demand is created. Set it to 30 and basically every 30 days it will generate a PO suggestion (while also looking ahead 30 days and grouping that demand into the new po suggestion). I’ve seen it suggested to do these days of supply in multiples of 7 days.
the above link is where I got some of that information.