DMC3 Fallen Angel question

My current go-to method to deal with them boils down to building RG's rage meter to the fullest and then doing a royal release once there's an opportunity. However, there are occassions when doing so would not damage them at all, despite Dante doing the royal release animation and the rage meter getting spent. Yet in other instances it works just fine, although I dont seem to do anything differently. Is there somethign I am missing?

https://imgur.com/a/VFuWKAg - clip of royal release not doing damage despite connecting

https://imgur.com/a/2WAmEc6 - clip of royal release doing damage just fine