It's a bug, not from you. From appthem's devellopers.
No coupon in a store is a basic situation. They're no test this. They're no debug seriously.
There is lot of bug...
for the url, they're make a variable $stores_url with a get $post_ID, but if there no coupon it was evident than it's return 0 (in a array 0 = the first post met).
Ok, in taxonomy-stores.php change:
$stores_url = clpr_store_url($post->ID, APP_TAX_STORE, 'term_id');
to
$stores_url = get_metadata('stores', $term->term_id, 'clpr_store_url', true);
if a developer goes here by a miracle, he says if it does not cause any problem.