A linear operator bounded in all Besov but not in Triebel-Lizorkin spaces

We construct a linear operator T: S'( Rⁿ)→ S'( Rⁿ) such that T: Bpqˢ( Rⁿ)→ Bpqˢ( Rⁿ) for all 0<p,q≤∞ and s∈ R, but T( Fpqˢ( Rⁿ))⊂ Fpqˢ( Rⁿ) unless $p=q$. As a result Triebel-Lizorkin spaces cannot be interpolated from Besov spaces unless $p=q$.