This might occur when there is a record in the [sys_rollback_context] which is left in the 'In progress' (in_progress) or 'Currently rolling back (reverting)' . This prevents the platform from executing any other rollback.

Run a script in the background script to change the state of the active record in sys_rollback_context table to Rolled back.

fixContextState();
function fixContextState() {
    var gr = new GlideRecord('sys_rollback_context');
    gr.get('___SYS_ID_OF_SYS_ROLLBACK_CONTEXT___');
    gr.state = 'recorded';
    gr.update();
}

Please Mark Correct if this had helped you.