Forum threads not filtering

Hi Everyone,

I have received some feedback from one of our members. They are unable to filter the forum thread posts in our different discussions groups. I have the option to do this turned on, but when selecting the different filtering options nothing changes. This makes it difficult for members to find their posts. Does anyone know why thing might be happening? or not happening I should say?

see screen grab below:

Thanks in advance for your help

Steph