Most such problems go back to what was or wasn't done when planting.

The root ball must be opened up before planting. If container grown, the roots are becoming root bound by the container.

The root ball must be moist before planting. If not, it must be soaked before planting.

The site must be amended with good acidic soil and provide good drainage. Without good drainage, most azaleas won't live very long. A raised bed will help provide good drainage in clay soil regions. Your soil must already be acidic if you are getting good green leaves, not yellow leaves.

Azaleas must be kept slightly moist during dry periods. A good mulch layer will help achieve that.

In Texas where the sumer sun can be severe, shade is necessary on many varieties. I am not sure how sun-tolerant Formosa is.

I areas like Texas, be sure not to water with alkaline water. Usually rain water is good if you can collect it with a cistern type arrangement.

If they weren't planted correctly or in a good location, you can did them up and replant them correctly in a good location. Just be careful not to damage the small roots too much. The small roots are the ones that the plant uses for water and nutrition. The large roots are just for support.

Here is a link that might be useful: How to grow azaleas