That's probably the way it's supposed to be. The trim shifts account for the fact that you need different FD positions for different RD positions. For the small-to-large FD shift, you should already be on the 1st trim click if you are on an outer rear cog with the inner chainring. Then it would be only one click to upshift the FD. Likewise moving the other way. For a large-to-small FD shift, if you were on an outer rear cog, you'd stop with one click of the FD, but if you were on an inner rear cog, you'd need 2 (or would be at the intermediate trim to start with.