What kind of fertilizer did you use? Azaleas have a dense network of surface feeder roots and many of the dry products could burn those. If your product came with instructions to scratch into the soil, that can further damage that fine network of roots.

If growing them in a soil of their preferred ph, they often need no fertilizer at all, they are not heavy 'feeders'. The most successful fertilizer if you are in need of one (fertilizing in response to symptoms they have shown) is slow release organic Hollytone, and even then applied about half the strength of the package directions.
I have acidic soil and never have seen reason to fertilize mine. They are top dressed with compost each year and that seems to be enough.

The only resolution I know of worth trying is flooding the bed with copious amounts of water, with the goal being trying to move the fertilizer down farther into the soil below the roots...but early after the application.

why did you think they needed feeding... they arent grandchildren ...

ken