[42.7.0] [rev:28118] Manual melee floor attack with small blade sometimes triggers regular attack, not ground attack

[mrk]

Version: [42.7.0]
Mode: [Singleplayer]
Server settings: [N/A]
Mods: [None]
Save: [Old Save]
Reproduction steps:

 

1. Have auto detect prone zombies OFF
2. Have a short blade equipped
3. Hold down the aim button, then hold down the manual floor attack button
4. Attack a zombie on the ground
5. A regular stab is triggered instead of a floor attack

 

I cannot consistently reproduce this. I'm usually hopping over short fences and hitting zombies after they fall over short fence or mid ground-lunge attack. It feels like the auto-detect prone going haywire, but I have that setting off, so probably unrelated? This only occurs with small blade weapons as far as I can tell.

 

I have manual floor attack bound to numpad 1, which is mapped to a mouse button with Logitech Gaming Software. I would think that might have something to do with it, but seems a little doubtful given that this seems to only occur with a particular type of weapon.