Yes, deon, it's happened ....
... to me and probably everyone else who has read or will read this thread.
I've never fished in your neck of the woods, but I have a vague recollection that someone talked about a similar situation recently where the fish were not keyed on the hatching insections, but on the chubs which were hitting the hatch. Maybe that is what was happening and why you caught the chubs and only one trout on a streamer which was taken as a chub.
Just something to keep in mind, by the way. Sometimes the most effective way to fish to rising trouts during a hatch is to run a baitfish style streamer through the rising fish high in the water column. The reason it works ( Art Lee wrote an article on this technique for Fly Fisherman magazine about 25 years ago ) is that the baitfish are feeding on the insects near the surface and the trouts, when they get the opportunity, snack on the baitfish rather than the bugs. I've fished a good number of hatches this way on streams and rivers in the Intermountain West with some great results, both for quantity and quality of trouts taken with the streamers.
Something else you might try, if the fish are feeding in wadable water. Walk out in the middle of where they are feeding and scoop up everything you can on and just under the surface. That should give you some ideas about the kinds of flies that will work. Kind of screws up the fishing temporarily, but it can be an invaluable "waste" of fishing time.
John
The fish are always right.