Movement bug: Cant use more then one key at once

What I expected to happen was...:
me being able to use more then one key like a and w to strafe or w and space to jump and sprint.

What actually happened was...:
just moved in the key i first pushed down
ex: cant us a and w at the same time unless i hold w and tap a twise (same with any other movement key) it sometimes doesnt happe but very rarly.

Steps to Reproduce:
To be honnest i got on minecraft for an hour or so, went to download a new game off of steam it did the useual start up downloads, went back to minecraft and noooow im what seems like ghosting (cant use more then one key) so i cant tell you how it happend or i would have already fixed it :/

Yes i have an anti ghosting keyboard. this just started yesterday. Also this does not happen on any other game but minecraft