LinearVelocity behaves differently when massless parts welded to character

Hi all,
I have a dash script that uses linear velocity. Normally, it works just fine.
However, I have a shield model, that, when welded to the character, causes the dashes to make the player dip below the ground.
This has been frustrating me for a while. I’ve checked and checked again. The welded part is client only, massless, not anchored, all the works.
For further troubleshooting, I’ve changed the linear velocity to force-limitaxis mode, or whatver it’s called, and set the max Y force equal to 0. Without the welded part, this works fine, but as soon as I add the welded part, the dash no longer works.
Wondering if there’s any way to fix this.

Ok, I found a solution like 5 minutes after posting this.
Apparently, linear velocity doesn’t respect massless. To fix this, you have to enable “CustomPhysicalProperties” of the part, and then set density to 0 (I set all custom physical properties to 0 but I’d imagine just doing density should work).