CR Frankel conjecture for spherical CR manifolds

Let $(M,J,\theta)$ be a closed, spherical, strictly pseudoconvex CR $(2n+1)$-manifold with vanishing first Chern class

$$c_1(T_{1,0}M)=0,$$

where $n\geq 2$. A contact form has CR-pluriharmonic $Q$-curvature when its CR $Q$-curvature has that property, and let $R$ denote the Tanaka–Webster scalar curvature. CR Frankel conjecture. If $\theta$ has positive constant Tanaka–Webster scalar curvature $R$ and its CR $Q$-curvature is CR-pluriharmonic, then the universal covering of $M$ is CR equivalent to the standard CR sphere $(\mathbf{S}^{2n+1},\widehat{J},\widehat{\theta})$. The paper presents this as a CR analogue of Frankel's conjecture and subsequently states that its asserted conclusion is obtained under the stated hypotheses; the supplied parser gives no explicit resolution status, so the database status remains open.