I see two closed threads related to this, but it still appears to be occurring (at least for me.) The summoned vale spirit attacks enemies when initially summoned but after a few moments, stops attacking completely although still orbiting the player character. Recasting initiates its attacks once more.
If it is intended to be a temporary spell, the vale spirit should disappear at the expiration of that time (and perhaps the spell cost should be reduced.) If it is intended to be a constant presence, it should attack consistently (maybe with a reduced reserve of mana to account for its persistence.)