So when I play 1.15.1 whenever I attempt to change resource packs on 1.15.1 it tends to cause fps lag despite in F3 the fps does not change or go down whatsoever the only way I can describe it is.

Before Changing Resoure Packs: 60fps display in terms of smoothness (despite in both instances it shows 200+ fps)

After Changing Resource Packs: 30fps display in terms of smoothness (despite it still saying 200+ fps

it feels as though when even switching resource packs it's still feels like it's locked to 30 fps even though the fps counter shows 200+ but if I restart minecraft it seems to fix the issue and makes it feel like 60fps again I'm thinking that it might be a new issue with the new rendering engine that minecraft java has implemented.

https://www.youtube.com/watch?v=9Gdlb72u7ws

I tried my best to recrate the Issue Above.

My Hardware is

Ryzen 5 1600x @3.6ghz

RX580 8GB