Search opencart 3. How to change case sensitivity?

Question

opencart

The site is on opencart 3
Theme is not standard, translated manually
I observe the following, when I drive an English product into the search, the search does not respond to case, that is, capital letters are ignored
But when I drive the name of the Russian product in lowercase into the search, the store does not find the product , you need to drive everything with a capital letter
How can I solve this issue?
And where is the search module itself in the standard opencart 3?

Answer 1

And where is the search module itself in the standard opencart 3?

Public_html/Catalog/Controller/Common/Search.php