[Rendar]

This has been a thing for as long as I know, but moves that have split damage type, that have an On-Hit effect (On High's Airborne on hit or Hexer's Black Bubble come to mind).

If you dodge both hits, you do not get afflicted.
If you dodge ONE of the hits, you have to roll the affliction chance.
If you get hit by both of the hits, you have to roll the affliction chance.

It's just a bit weird that you have to get a glancing on both hits to not get an affliction chance to roll. Frankly, it might not even be a bug, but I figured I might as well bring it up as a query

[Raigen.Convict]

Personally, the main class that does this is Hexer, who's whole point is inflicting status effects, and I believe it was made this way to ENCOURAGE using them for the dual chance to inflict feature. Similar to the advantage of crits with multi-hit weapons. Or even just hit chance with multi-strike weapons.

[Neus]

Not a bug. If a skill does multiple instances of damage and applies an effect that requires it to hit, only one of those instances has to hit.