They need shade, at least afternoon shade. IME, none of the arborescent type hydrangeas do very well in full sun, wilting miserably daily during the summer.

I have an Annabelle in similar conditions (northern exposure) and it has done well because the shade is "bright shade".

I had invincible spirit on the north side of my garage, it died the next year. I also tried it on the south side, but no luck. Finaly gave up on that type and kept planting other macs and pee-gee types.