[Gelöst] Custom search query is not working

Background of the issue:
I am developing a custom shortcode that is showing a list of custom post type and having a search box at top. I am using default WP_Query to get the result. I tried the same code on a different site where we don't have WPML and the result is showing as expected.

Symptoms:
When I try searching a keyword, it is loading result from default post, rather than custom post result.

Questions:
Can you please help me to troubleshoot this issue?