php upgraded from 7.3 to 8.1, then in logs:

/var/www/job/core/event_api.php: 232: - - - - event_callback()
/var/www/job/core/event_api.php: 164: - - - - event_type_execute()
/var/www/job/core/bugnote_api.php: 315: - - - - event_signal()
/var/www/job/bug_update.php: 466: - - - - bugnote_add()" while reading response header from upstream, client: 172.16.7.16, server: xxxxxx.com, request: "POST /bug_update.php HTTP/2.0", upstream: "fastcgi://unix:/var/run/php/php8.1-fpm.sock:", host: "xxxxxx.com", referrer: "https://xxxxxx.com/bug_change_status_page.php"
2023/03/09 13:44:15 [error] 55460#55460: *409832 FastCGI sent in stderr: "PHP message: Unknown named parameter $files

comment saved with INTERNAL APPLICATION ERROR

if change status without comment - works fine.