When having executed a full load to a delta enabled target, the next delta request cannot be activated anymore. (The full load is hampering this)
Solving this issue by deleting this full load can be a solution, but it’s easier to reset the full load to a full repair load.
The latter can be accomplished by executing report RSSM_SET_REPAIR_FULL_FLAG.
(Tcode: SA38 -> RSSM_SET_REPAIR_FULL_FLAG)