"Default Subscription Period" ( Home > Products > Service Plans > PlanID > Publication Settings) is set, store is synchronized but in the on-line store a different subscription period is selected by default and put in the order cart.
The issue is caused by the bug with id #PBA-52960. The bug is reproducible when the parameter
SINGLEPLAN_EDIT is set to
true on the store screen (one service plan in the sales category).
As a workaround use
Sort Number in the subscription periods settings (periods without the sort id are on the top, then in ascending order) or reconfigure the store so that the bug above is not reproduced.