i think this is the right vid showing

[turbid oriole]

It would be preferable to see the particle system modules as well

[velvet star]

oh ye sure, ill do that

[velvet star]

ok, first bit:

[turbid oriole]

I don't see anything that sticks out
Mostly just wanted to confirm it's not a VFX graph where the bounds method must be defined manually
Particle Systems should always generate the bounds automatically, but seems that there's at least one exception
https://issuetracker.unity3d.com/issues/particle-bounds-are-displayed-incorrectly-until-a-change-is-made-in-the-particle-system-when-the-particles-are-generated-by-code

I doubt the "show bounds" checkbox yields any useful information but may be worth a try

[velvet star]

nah it shows nothing sadly

[velvet star]

that could be the issue

i am setting all my particles manually by code

(im doing fluid physics and am using the particle system as a quick way of visualizing it)

[turbid oriole]

Fixed in 2020.1.X, 2020.2.X

[velvet star]

ye, weird

im definitely in the latest 2021 version

guess ill just specify the bounds manually

[turbid oriole]

It might turn out to be a trivial solution to set them manually

Especially if it's just for testing

[velvet star]

it shouldnt cause too much lag if i set them to some large number right?

[turbid oriole]

Not inherently, bounds just prevent culling

[velvet star]

ok nice, thanks a ton!

[turbid oriole]

Also be used to determine if lit material particles fall under a light's range in forward rendering, though I doubt that's relevant

[velvet star]

im mainly using unlit shaders luckilly, (my computer is a tad old and cant really handle lit shaders too well)

[turbid oriole]

With big lit systems it would be revelant considering all the particles would be rendered wholly anew for every light