Invinsible cleric beast after 1st fight with it

So I just had a really weird one. 1st time I fought cleric beast everything was normal... but the 2nd time it was invisible. I beat it like that 3rd time lmao. So... does anyone have a fix? D: here is the vid if someone wants to see, just skip a little ahead for the fight

https://www.youtube.com/watch?v=scUtV3xHjq4