Sprite causing small freeze on play animation

Hi All

I am coming across an issue where my game is freezing/pausing momentarily when playing a spritesheet animation.

The spritesheets are on the large side between 3k and 4k pixels, and it only seems to happen the first time it plays (i have tried to play it when everything is created to get around this with no luck). Would the size of the texture being used be part of the problem?

Has anyone come across this? and if so, did you manage to solve it?