Hey @FrailWarbler515! Welcome to the forums!
Do you know if your death animation uses root motion?
If so, it may be sending the root below the floor collision as part of the animation, so when you respawn, if the animation is still active and it’s not yet fully transitioned to the idle state, that would put the collider inside of the floor, causing it to bypass the topside collision. That’s the first place I’d look. To test that out, you can move the spawn point higher up, causing the player to have to fall to the floor once they respawn.
Let us know how that goes! 