Revit's inability to snap or manually align annotation object have long been a frustration to those that have adopted Revit. Jordan Musset shares a little secret that he likes to use with sections for precise placement.
Sections can be a little finicky in terms of being able to place them exactly where you want them. A technique to place them where you want them is as follows. If the section is to be placed exactly in the middle of the expansion joint, follow these steps.
Sections will not use detail lines as a reference and it is difficult to move sections into place after they have already been created. Mostly because the snaps don't always pick up pertinent references within them. Draw a reference plane that is placed specifically where you want the section.
After that, place the section with two clicks, making the two clicks the beginning and end reference of the reference plane. Now the section is placed exactly where intended. Also recommended, delete the reference plane and pin the section in place.