Hi Peter, it’s generally accepted in music notation that although shorter notes get given less horizontal space than longer notes, this isn’t usually proportional; bars with lots of semiquavers (16th notes) will be wider than bars with only crotchets (quarter notes). Adjusting the note spacing as suggested above will get you closer to proportional notation - you can also search the forum for “proportional notation” to see what other users have discussed about this and the settings to use (such as this thread: Spacing ratios).
Do also try increasing the amount Dorico can compress lyrics and reducing the minimum gap between lyrics, for example, to reduce their impact on horizontal spacing.