Your character fell under the ground and his coordinates are saved as such in the db.
When in play mode, go to World Outliner, click on ViewOptions->World->Server, then search for “player” in the outliner, look for BP_MBP_ModularPlayerCharacter_C, select it and change its position, in particular set the Z axis to 21000 or higher.
Your character will find itself above ground and from then on it will save into db with correct coordinates.