… and the camera moves the exact opposite direction, or even 90 degrees rotated from what you expect, check that your Spawn Points’ transforms are not rotated, as that is the rotation that gets applied to the Player object and everything that is a child (your Player Camera) and everything spawned from it (including the Base).
E.g. if your first spawn point is rotated 180 degrees, then the first player’s camera will be inverted in both the left/right and up/down directions.