[BUG]: Armored Core Nine Breaker - Stuck/Broken AI on Some Levels

[forrvalhalla]

Describe the Bug

In Armored Core Nine Breaker, missions that feature small floaty enemies that appear from doors/hatches will get stuck in those doors, never leaving their initial spawn location. In some missions that have this issue, frequent hanging occurs too (Hit > Melee 2 for example). This seems to be a long-running issue, as even on 1.6 these same AI are broken.

Here's some examples of what I'm talking about, you can see here on PCSX2 how the AI won't move from spawn. https://youtu.be/-EyFNgUC8fw?t=28

And yet on real hardware, they do leave spawn. https://youtu.be/BY4Dtf6e8po?t=41

I'm not entirely sure if this is an AI-related issue or a collision related issue. I've tried messing around with the rounding/clamping settings to no avail, but there's a chance I'm just doing it wrong.

Reproduction Steps

(Reproduction steps shown in videos)

1. Start a new game
2. Go to Training
3. Select Attack > Judgement

Expected Behavior

AI should leave their spawns and chase the player.

On emulator, they get stuck and never leave the spawn door.

PCSX2 Revision

v1.7.4344 , v1.6.0

Operating System

Windows 10 (64bit)

If Linux - Specify Distro

No response

CPU

i5-7600K

GPU

GTX 1050ti

GS Settings

Default

Emulation Settings

Default (Tested MTVU off)

GS Window Screenshots

(not a GS-screenshot, but a GIF that shows the AI stuck in place.)

Logs & Dumps

No response

[Berylskid]

Does it occur even on Software renderer?

[forrvalhalla]

Yeah it does. Tried all renderers too.

[ghost]

@forrvalhalla Set the ee to interpreter and see if it solves it

[forrvalhalla]

Didn't work when I tried it on 1.6. Couldn't find the setting on Nightly, but if it's called Enable Cache then I tried that too.

[MercuryAmalgam]

disabling recompile fixed the bug for me on nightly it's in advanced > Emotion engine > enable recompiler FPS is unplayable without recompiler though

[refractionpcsx2]

can you try other things such as setting the EE clamping to "Extra + Sign" or disabling Fast Memory, INTC Spin, Wait loop etc? maybe increase the EE Cycle Rate to 300%.

See if any of those help

[forrvalhalla]

None of them seem to help sadly. Disabling EE recompiler immediately fixes it, but tanks the framerate just like @MercuryAmalgam mentioned.

[refractionpcsx2]

bummer :( okay, thanks

[Mrlinkwii]

i assume is also broke on 1.4 etc

[forrvalhalla]

Just tested, it's also an issue on v1.4, v1.6, and some random v1.5 version I had laying around. Issue is also present on NTSC-J.

[AmyRoxwell]

Tested on latest nightly. Still borked and only way to fixed it is by turning off recompiler (BYE BYE FRAMES)

[Goatman13]

Untested, but this could be similar issue as in https://github.com/PCSX2/pcsx2/issues/8407 (fpu div rounding).

[AmyRoxwell]

Latest nigthly still borked: Changing DivRoundMode does nothing.

[AmyRoxwell]

Tested on PCSX2 v2.1.226, Still broken. Changing these settings have no effect, only way to "Fix" it is disable the recompiler.