Bad Gateway (docker)

I was running Librenms on docker for some time but suddenly got the message Bad Gateway.
I’ve run ./validate.php inside docker got the following

bash-5.0# ./validate.php

Component Version
LibreNMS 1.58
DB Schema 2019_04_22_220000_update_route_table (147)
PHP 7.3.13
MySQL 10.2.27-MariaDB-1:10.2.27+maria~bionic
RRDTool 1.7.2
SNMP NET-SNMP 5.8

====================================

[OK] Installed from the official Docker image; no Composer required
[OK] Database connection successful
[OK] Database schema correct
[WARN] IPv6 is disabled on your server, you will not be able to add IPv6 devices.
[WARN] Updates are managed through the official Docker image

any idea why this happening?

This has been fixed, see https://github.com/librenms/docker/issues/71