Haven’t put in a ton of time fishing flats on the section of river between St Anthony falls and the coon rapids dam but certainly done my fair share with no big fish to date. But, I have caught plenty of juveniles(<3#) fishing for other species dragging worms, soaking for channels, etc. I find it odd.
If one catches plenty of youngsters but can’t find a big one what should a guy do? Start exploring new habitat, spots, bait? One has to assume there will be big fish around wouldn’t ya?