Walking/Sprinting switching randomly

Walking Forward makes character to switch randomly between walking and sprinting, also happens when crouching, character moves slower than normal.
Nothing seems to fix it, restart, re-install, update driver/java, disable shaders, disable optifine, etc...

I have a video but it exceeds the upload limit so I'll post the link to YT: https://youtu.be/wxbRwfnwBaU