Let $H$ be an infinite dimensional separable Hilbert space and $B(H)$ the algebra of bounded operators.

Invariant subspace problem: Let $T \in B(H)$. Is there a non-trivial closed $T$-invariant subspace?

Remark: This problem is known for the Banach spaces in general, but still open for an Hilbert space.

Let $(e_{n})_{n \in \mathbb{N}}$ be an orthonormal basis.
Definition : $T \in B(H)$ is banded if $\exists r \in \mathbb{N}$ such that $(Te_{n}, e_{m})\ne 0 \Rightarrow \vert n-m \vert \leq r$.

Remark: A banded operator is a thick generalization of a diagonal operator. It's also a finite sum of finite product of (orthonormal) weighted shift operators (which check obviously the ISP).

Question: Do the banded operators check the invariant subspace problem ?

Remark: Here is a question on MSE : Is every operator unitary equivalent to a banded operator ?
N. Ozawa answered "no" in its comment below (see also sections 16.3 and 16.4 of its book here).
D. Voiculescu gave examples of quasidiagonal operators which don't generate exact $C^{*}$-algebras:
A note on quasidiagonal operators, Operator Theory, 1988, 265-274.
Question: Do these examples check the ISP ?