Of course! Here’s the (simplified) code and the attached screenshot of the back-end data. The back-end is in french, hope it won’t cause any problem.
<?php elseif(get_row_layout() == 'image-5') : ?>
<?php var_dump(get_sub_field('keep_grouped')); ?>
<?php endif; ?>
I’ve been able to make it work correctly outside of a Flexible Field.
Thank you!