It looks like the author made the opposite claim three years ago:
http://math.ahu.edu.cn/_upload/article/files/85/03/f191ded54...
http://math.ahu.edu.cn/_upload/article/files/85/03/f191ded54...
[1] https://web.archive.org/web/20220128195023/https://motls.blo...
On their arXiv page: https://arxiv.org/abs/2006.12546, the author states that "though all my previous proposed (dis)proofs were flawed, i think the flaws pointed me towards the right direction..."