2010 manual hesitates/clunks when shifting into 5th sometimes

[Danzka]

Hi everyone, I have a 2010 Audi with about 90K on the clock.  In the past couple of weeks, now and then, when I change into 5th, there's a slight hesistancy and a clunk, then it carries on as if nothing has happened.  Has anyone else had this problem before and discovered what it was caused by.  Many thanks in advance.