I posted this bug report in season 17. But the basic understanding of this bug is that, during epiphany, if you have a high latency, tied with a high attack speed, you will not gain the damage bonus of Kyroshiro’s Blade. Your damage is effectively cut by 1/3rd if affected by this bug, since the Blade is not counted. No I don’t have hopes for this development team to fix this.
If you want to experience this bug yourself, connect to a different country server (Ex. North America user connecting to Europe servers), slap on a Gogok of Swiftness, use the 30% Atk Speed passive, and watch your damage plummet.