Instant cast second cooldown while recast

Hi,

So I'm not sure if it is a bug or normal. Here's a recording of what I'm talking about. It happens anywhere, in solo or party, while attacking or not.

https://www.youtube.com/watch?v=vrBd...ature=youtu.be

Time: 14h45 - 23/06/2017
Frequency: Immediately after skill cooldown reset
World name: Diabolos
Character name: Nano Wahrheit
Class/Level: PLD 54

Steps:
1. Instant Cast(Rampart/Fight or Flight/Anticipation, etc)
2. Waiting for cooldown
3. Recast right after cooldown finished
4. Gives a Not yet ready and another cooldown

Thank you.