In map services published from feature classes symbolized by a representation with markers between dashed lines, the markers are misplaced if the Endings property is set to 'No constraint'.

Workaround

Alter the Endings property for the representation in ArcMap prior to publishing. For example, set Endings to 'With half gap' for marker and to 'With half pattern' for Dashes, instead of 'No constraint'.

Steps to Reproduce