Weird blur-like bug when sprinting

It tends to happen rarely and sometimes. There's this weird bug in which when I run, the FOV like vision in first person blurs like that I don't even know how to describe, but I think it is like a zooming FOV. After some time or If I close the world and then rejoin again, it won't be there anymore. This bug is very annoying, each time to close and rejoin every time it happens.

I wanted to add an image of how it looked like, but it will be impossible as It is only when sprinting, making it hard to take the image.