One time one budgie of ours had a toenail clipped short at a vet exam, and it started bleeding heavily at home. Styptic stick didn't work. That finally got the toe to stop bleeding, but we watched carefully for some time to be sure. If you see one or more of these, or anything else odd or weird, don't waste time getting opinions from amateurs like me. Finally, sometimes the worst happens, despite the best care and the best vets.
Birds can and do die.
Sometimes it's from careless breeding, sometimes it's pure bad luck, or an accident, or maybe it's just time for the bird to pass on.