Shimano 7000 crankset spacers

Am upgrading from 10 to 11 speed and am attempting to swap a ten speed Tiagra 50/34 chainset for a new 11 speed 7000 50/34 chainset. The BB size is 68mm. When fitting the the RH part (the right crank and chainrings) when pushed fully through the BB, the crank arm just catches on the chain stay. The previous Tiagra chainset had a tiny amount of clearance against the chain stay, so I am wondering do I need a spacer between the 7000 crankset and the BB. If so, what type, how many and what sizes would I need, and would I need to install them on both sides between the crank arms and the BB. Any help would be gratefully appreciated.