The ARS lists Weston's Innocence. It is a cross of arborescens and viscosum. It is extremely hardy. It should be OK. I have a similar plant, Weston's Lemondrop in full sun and it is doing well. They are not drought tolerant. Mine struggled last summer when we had a bad drought. I had to keep it from getting too dry.
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Yours may have struggled initially when it was first planted because it may have come out of a greenhouse. If it was a field grown plant, then it should be OK.

They need some sun to set next year flowers. They will be set this summer. Yours should be OK since it gets afternoon sun during this period.

Here is a link that might be useful: Weston's Innocence

I've grown 'Weston's Innocence' in Manchester, NH (Z 5b)for 5-7 years. It was in our back gardens growing in dappled deciduous shade. The plant covered itself with flowers mid-to late June. It was fairly drought tolerent for us but did tend to suffer from powdery mildew in July/August...but never to the point of detracting substantially from the shrub. All-in-all, and after growing about a dozen of Weston's azaleas...I like them. My favorites are 'Parade' & 'Pennsylvania'.