Movement keys 'locking'

Hi.

I have found that in this and previous versions, the movement keys seem to 'lock'. I have spoken to people who deal with computers and they confirm that is nothing to do with my laptop. Further evidence for this is that this issue only arises whilst playing Minecraft.

There are a few things that I end up doing to attempt to fix this when it occurs is either:

1 - press 'esc' and then hitting the keyboard multiple times

2 - press the direction button twice (e.g. if stuck moving forward, I will double tap 'W')