Has anyone else had a this problem with dulux weathershield gloss,after using it and putting the brush in my brush mate box ,I come back the next day to re use the brush and it seems quite stiff,at first I thougt it might be the brush but I've tried several new ones with it and it does exactly the same and it's not the box cos other brushes are fine,I haven't got a clue why it never used to do this any help would be great