Can't sprint properly on 1.8

[Losaik]

Lately I've not been able to sprint at all on 1.8, I was wondering if anyone else has this problem. On other versions, using the same hardware, sprinting works fine. I also tried to bind my sprint key to another key, and turn off sticky notes and such. Nothing works for me. This is on vanilla btw.

Edit: forgot that I'm using optifine 1.8 and not vanilla, any optifine settings I should look out for?

Anyone got any fixes perhaps?

free plugins
minecraft paid for free
SpigotMC
minecraft plugins
mcmarket
mc-market
spigotmc
free minecraft paid plugins
free minecraft plugins
aac free
ewg free
Minecraft Premium Plugins
ewg free download
litebans free
epicworldgenerator free
free schematics
leaked schematics minecraft
schematics
schematics leaked
schematics free
minecraft schematics free
paid minecraft schematics free
paid minecraft schematics for free
free cracked plugins
free cracked minecraft plugins
plugins
featherboard download
featherboard plugin download
antiaura download
xenforo leaked
xenforo for free
xenforo addons