This is my first dipladenia and I’ve had it since May of 2026. It has done well growing and blooming. Until the last several weeks. It began with leaf yellowing and dropping. We’ve had a heat wave lasting for a couple of weeks so the soil felt dry and I watered thoroughly. No change. Then I’ve sprayed with Neem Oil because of white specks on underside. I’ve seen spider mites before and these didn’t seem like them but I thought I could be wrong. Advice would be appreciated.