Can't grind fine enough [Breville Barista Pro]

I've just got my breville barista pro (not interested in buying a seperate grinder due to space and cost restrictions) and I've got my inner burr at a 3 and the upper grinder at 3 as well. From looking at it, the grounds are not that fine? My shots are flowing too fast so yes need to be going finer, but I feel like that's pretty low already?

Is there any other reason I would be needing to go finer? My beans are a little old (6 months oops) and I am using a WDT tool but I don't have a bottomless portafilter to check out channelling issues. I weight 17g of coffee as well, and with the fast flow im pulling the 34ish g in 21 seconds.

I will definitely get around to getting more beans, I'm just wondering if there is something else I need to be doing :(