Pagination issue in a category page [WordPress]

[[email protected]]

I wanted to show one category posts from all custom post types, which my code does very well but pagination just stopped working.
here is my code:
My code sample

If I set 6 post per page in WP dashboard reading section it only shows 6 posts and if i click to pagination nav to go to second page page it displays nothing.

Same thing if i set 2 posts per page, doesn;t show anything on other pages.
Please help.

[Author]

Posts