not typical. Usually they loose one at time and alternate sides. As nature they would have to be able to fly to keep up with flock and escape predators.
A quick way to share pictures. Click go advanced under text box, then click paperclip, then choose picture , then hit upload on far right, when loads close window and post.
Maybe if we see what's going on we will hsve better idea.
What dies your bird eat? If you haven't yet offer leafy greens like romaine, bok choy, Swiss chard, hang the leaf or weave in cage bars. Budgies will nibble, and gives them lots of good nutrients and vitamins. My budgies eat every single veggies on the safe parrot list. they also like the rare raspberry, or blackberry, ir strawberries, or cranberry. No grapes, to sugary not enough nutrients.