For the Aberrant Mind sorcerer origin, it’s lv 18 ability, Warping Implosion, reads as follows:
You can unleash your aberrant power as a space-warping anomaly. As an action, you can teleport to an unoccupied space you can see within 120 feet of you. Immediately after you disappear, each creature within 30 feet of the space you left must make a Strength saving throw. On a failed save, a creature takes 3d10 force damage and is pulled straight toward the space you left, ending in an unoccupied space as close to your former space as possible. On a successful save, the creature takes half as much damage and isn’t pulled.
So, if you teleport to within 30 feet of where you were before, do you need to make a saving throw and potentially take damage and get sucked closer? I can see this playing out one of two ways
Since the saving throws are made right after you disappear, you haven’t reappeared yet and are thus unaffected
Since it is teleportation, the moment you disappear you also reappear in your new location and thus would be affected