"X-Forwarded-Proto" header causes Omada Controller v5 to return 404

Setting the X-Forwarded-Proto header causes the Omada Controller to 404.

Using controller 5.3.1 on Docker (https://github.com/mbentley/docker-omada-controller).

With header:

curl -kv https://localhost:8043/<id>/login -s -o /dev/null -H 'X-Forwarded-Proto: https'
*   Trying ::1:8043...
* Connected to localhost (::1) port 8043 (#0)
<snip>
> GET /<id>/login HTTP/1.1
> Host: localhost:8043
> User-Agent: curl/7.74.0
> Accept: */*
> X-Forwarded-Proto: https
>
< HTTP/1.1 404
< X-Frame-Options: SAMEORIGIN
< X-Content-Type-Options: nosniff
< Strict-Transport-Security: max-age=31536000; includeSubDomains
< Referrer-Policy: strict-origin-when-cross-origin
< Content-Length: 0
< Date: Thu, 02 Jun 2022 23:41:07 GMT
<
* Connection #0 to host localhost left intact

=============================================================================
Without header:

curl -kv https://localhost:8043/<id>/login -s -o /dev/null
<snip>
> GET /<id>/login HTTP/1.1
> Host: localhost:8043
> User-Agent: curl/7.74.0
> Accept: */*
>
< HTTP/1.1 200
< X-Frame-Options: SAMEORIGIN
< X-Content-Type-Options: nosniff
< Strict-Transport-Security: max-age=31536000; includeSubDomains
< Referrer-Policy: strict-origin-when-cross-origin
< Content-Type: text/html;charset=utf-8
< Content-Language: en-US
< Transfer-Encoding: chunked
< Date: Thu, 02 Jun 2022 23:42:35 GMT
<
{ [3658 bytes data]
* Connection #0 to host localhost left intact