@jamiayh i haven't experienced this bug personally, but it's apparently a pretty common glitch that hits new players when they reach level 6. @SalixCat has recommended this as a temporary workaround:
For some players typing more than 22 random letters has solved this problem.
Another option is to delete the progress and restart the game from level 1.
There's an open thread in Bug Reports collecting info from all the users that have this issue, so I'd recommend adding your details to that! @EA_DragonsEye has requested all players experiencing this glitch to DM them your player ID and a brief explanation of what you're experiencing so that they can follow up.
It seems to be impacting quite a significant proportion of players so hopefully by the next update it will be resolved.