apps/richdocuments/settings/fonts.json returns proper data but also error code 404

[coRpTitan]

Describe the bug
I have app called richdocumentscode, and it does not work. In the logs, I can see error message:
wsd-16696-16732 2025-11-21 13:25:35.749867 +0100 [ remotefontconfig_poll ] ERR Remote config server has response status code: 404 (Not Found)| wsd/RemoteConfig.cpp:133

When I try to open URL manually, it gives me some content, by looks of it it looks correct, but HTTP header gives 404 instead of expected 200:

$ curl -I https://.../apps/richdocuments/settings/fonts.json
HTTP/2 404
x-powered-by: PHP/8.4.14
...
content-length: 2296
content-type: application/json; charset=utf-8

Actual content - start of it:
 curl https://.../apps/richdocuments/settings/fonts.json
{"kind":"fontconfiguration","server":" (https:\/\/...)","fonts":[{"uri":.....

Plugins config:

 php occ config:list richdocumentscode
{
    "apps": {
        "richdocumentscode": {
            "enabled": "yes",
            "installed_version": "25.4.702",
            "types": ""
        }
    }
}

php occ config:list richdocuments
{
    "apps": {
        "richdocuments": {
            "disable_certificate_verification": "",
            "doc_format": "ooxml",
            "enabled": "yes",
            "installed_version": "9.0.1",
            "public_wopi_url": "https:\/\/...",
            "types": "filesystem,prevent_group_restriction",
            "wopi_allowlist": "192.168.0.0\/16",
            "wopi_url": "https:\/\/...\/apps\/richdocumentscode\/proxy.php?req="
        }
    }
}

All apps are updated:

• richdocuments: 9.0.1
• richdocumentscode: 25.4.702

php occ app:update --all
All apps are up-to-date or no updates could be found

Expected behavior
When URL exists and returns some data return code should be 2xx, not 404.

Any idea why is this happening?