It needs more moisture. Camellias like contant moisture, not dry nor wet. Many of the roots are in the top few inches so you want to feel moisture at depth of 4" or so, not at 10".

Insert a finger to a depth of 4" and see how it feels. If it feels wet, take no action. If it feels moist, do the same. If it feels dry or almost dry then water. Put about 3-4" of mulch and keep the pot away from windy areas. Test with the finger method daily for about two weeks. Every time that you water, make a note on a wall calendar. After two weeks, observe how often you are watering (every 2/3/4/etc days). Then make a habit to water on that same frequency. If the temps change more than 10 degrees and stay there, use the finger method again. Lack of moisture will cause the plant to drop the flower buds.

Great info, thanks Luis! I will do that and hopefully it'll recover. The 3 in ground camellias are indeed in moist soil, this one is potted and dry.