Correct positioning for caesura input
Caesuras are commonly placed at the end of a bar, before a barline. In Dorico, caesuras must be attached to the note immediately after the position you want it to appear, as then Dorico can automatically position them correctly.
If you input caesuras with your mouse input preference set to Load cursor with item, you must click the first note in the next bar for a caesura to appear before the barline. You can also click directly on the barline.
When input correctly, the dotted guidelines link the caesura to the notehead immediately after the barline.
If your dotted guidelines do not link the caesura to the notehead immediately after the barline, delete the caesura and re-input it. Caesuras can cause spacing issues when input incorrectly.