---

Claim. Hangdi Chen and Yaojun Chen, Counterexamples to two conjectures on the diameter of clique-free graphs, state in their abstract a construction that disproves the amended conjecture of Czabarka, Singgih and Székely, including its $k$-colorable version, for every $k\ge7$ and sufficiently large minimum degree, and, when $k=2r\ge8$ and $3r-1\mid\delta$, part (ii) of the statement of Problem 612: connected $K_{2r+1}$-free graphs of minimum degree $\delta$ whose diameter exceeds $\frac{3r-1}{r}\frac n\delta+O(1)$, for every $r\ge4$ and every sufficiently large $\delta$ divisible by $3r-1$.

Covers. Part (ii), in full if the claim is accepted: part (ii) is asked for every $r$, so a refutation for every $r\ge4$ disproves it. Part (ii) is the question that the refereed counterexamples to part (i) leave open; since part (i) is already disproved, accepting this claim would make the problem disproved. It does not bear on part (i).

Standing. A preprint (arXiv v1 of 3 September 2026, the only version found), unrefereed; the preprint is not held, and this page cites its abstract; no outside review was found. A thread comment of 4 September 2026 reports the result; the site marks comments as unverified. The claim stays claimed, and part (ii) stays open until a refutation of it is accepted.