The index view logic is problematic, hiddening valid questionnaires and allowing view of templates.

In the file: index.php
line 47 is as follows(in 1.9.x code, and similarly on 2.x):
$realm = get_field('questionnaire_survey', 'realm', 'id', $questionnaire->id);
which causes this problems, since it should be:
$realm = get_field('questionnaire_survey', 'realm', 'id', $questionnaire->sid);

best regards
--dhg<at>atarplpl.co.il