WordPress with Photocrati Theme keeps resetting site URL – help solving underlying problem

If this is done via WP Options API (as opposed to direct SQL query on database) you can use hooks to log it.

Something along the lines of (not tested, make sure it works under normal option save first):

add_filter( 'pre_update_option_siteurl', function ( $value ) {

    error_log( wp_debug_backtrace_summary() );

    return $value;
} );

Next time it happens you should get much better idea about underlying reason from the backtrace.

Until you got it fixed you could also hardcode this into configuration to prevent breakage itself:

define('WP_HOME','http://example.com');
define('WP_SITEURL','http://example.com');