If you specify markers with the plot, then the data skin affects the markers as well.
Table 7.29DATASKIN Options for Markers
NONECRISPGLOSS
MATTEPRESSEDSHEEN
Default
NONE
Restriction
The ODS GRAPHICS option DATASKINMAX= controls the
maximum number of graphics elements that are skinned in a plot
statement. In the first maintenance release of SAS 9.4 and later
releases, the maximum number is 200 by default. When this limit is
exceeded for a plot, the specified data skin is not applied. Use the
DATASKINMAX= option to increase or decrease the maximum limit.
See
“Using Data Skins” ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month, and much more.