My "player" wont move by its velocity even though my code worked not long ago

[blissful sparrow]

I'm using Vector2d to represent location, velocity, and acceleration, and accel changes vel and vel changes position, but the code that's meant to change position by velocity doesn't seem to be working.
problematic method below, full class in another message as well as github link

public static void physics() {
        players.forEach(p -> {
            p.stopYMomentum = false;
            p.limitVel();
            p.lastPos = new Vector2d(p.currPos);
            p.currPos = p.currPos.add(p.vel); // TODO - THIS LINE DOESNT WORK
            p.vel.add(p.acc);
            p.acc.y = ((p.acc.y - p.gravC) * 0.85) + p.gravC; // normalize vertical acceleration towards gravC
            p.acc.x *= 0.95; // normalize horizontal acceleration to zero
            p.vel.mul(0.99f);
            boundaries();
        });
    }

[bitter flax]

⌛ This post has been reserved for your question.

Hey @blissful sparrow! Please use /close or the Close Post button above when you're finished. Please remember to follow the help guidelines. This post will be automatically closed after 300 minutes of inactivity.

TIP: Narrow down your issue to simple and precise questions to maximize the chance that others will reply in here.

[blissful sparrow]

here's the full Player class, and the full project is here in the overhaul branch https://github.com/Tors-0/postAp-project/tree/totalOverhaul
java version is temurin-20

[placid stag]

You should update the position after updating acceleration and velocity

[bitter flax]

💤 Post marked as dormant

This post has been inactive for over 300 minutes, thus, it has been archived.
If your question was not answered yet, feel free to re-open this post or create a new one.

[blissful sparrow]

got it to work but have no idea what was wrong, its just very touchy :P

changing certain bits of code outside the method somehow fixes and breaks it