can you just aim away from the wall if you're close to one ???
if you're touching the skybox and charging a big attack, the hit box from the beam is too big and touches the skybox after spawning ... that's no bug ... and it's not really fixable
try to use more melee, go away from walls and skyboxes, play more battlearena and Namek and don't be a coward who hide on the top of the map