Strictness of the Σ_n-correct forcing axiom hierarchy for n>2
Determine whether, for n>2 and any n‑nice forcing class Γ, the axiom Σ_{n+1}–CFA_{<κ}(Γ) is strictly stronger than Σ_n–CFA_{<κ}(Γ), i.e., whether Σ_{n+1}–CFA_{<κ}(Γ) does not follow from Σ_n–CFA_{<κ}(Γ).
References
We are left with the following open questions, where a positive answer to the first would easily yield a positive answer to the second: Is $\Sigma_{n+1}\mhyphen CFA_{<\kappa}(\Gamma)$ a strictly stronger axiom than $\Sigma_n\mhyphen CFA_{<\kappa}(\Gamma)$ when $n>2$?
— $Σ_n$-correct Forcing Axioms
(2405.09674 - Goodman, 15 May 2024) in Section 3.3 (Do Σ_n-correct Forcing Axioms Form a Strict Hierarchy in n?)