The Right Hand bearing should be seated all the way home as the first step as that determines the alignment of the rotor to the brake caliper.
The Left Hand bearing should then be pressed in until the spacer makes contact with both inners.
Read the bearing installation section in either of the service manuals that are downloadable from this site. The installation method in the manual assumes the use of the factory tool that applies pressure to both the inner and the outer to ensure correct alignment once the spacer contacts the two inners.
If you aren't using this tooling you need to be very careful to not set-up a side load condition.