How to track where a redirect is coming from in wordpress?

Question

WordPress

There is a wordpress multisite made on subdirectories (for different languages), after activating WPMS, all subdomains began to redirect to the main domain (there were no problems before WPMS activation). In principle, it is logical to choose the mode of subdirectories, not subdomains, but subdomains are also needed. I commented out everything in the code that even from a distance resembles a redirect, including the wp_redirect functions, nothing helped. The debugger does not determine at all where the redirect comes from, maybe someone faced such a problem on WPMS?

Answer 1

1 htaccess
2 redirect can be cached in the browser