Service worker returns Error 403 - Forbidden

[csolisr]

Describe the bug

The service worker, which is used by Firefish to fetch updates in the background, is not working properly, sending an Error 403 ("Forbidden").

Context

• Hardware: * Dedicated PC *
• YunoHost version: 11.2.5
• I have access to my server: *Through SSH, webadmin, direct access *
• Are you in a special context or did you perform some particular tweaking on your YunoHost instance?: yes
  • If yes, please explain: Using Wireguard to connect to an external VPS, in order to bypass the CG-NAT restriction from my ISP. See here: https://forum.yunohost.org/t/homemade-wireguard-vpn-on-a-vps-server/15662
• Using, or trying to install package version/branch: 1.0.3

Steps to reproduce

1. Log into the website
2. Wait for a few minutes. Notice that the automatic note updates are not working.
3. Check on your browser's console. There will be repeated warnings that a service worker is not connecting.

Expected behavior

The service workers should work as expected, fetching data in a regular basis.

Logs

From the console log:

Firefox could not establish a connection with the server at wss://sns.example.net/streaming?i=[redacted]&_t=[redacted].
The connection with wss://sns.example.net/streaming?i=[redacted]&_t=[redacted] was interrupted while the page was being loaded.
GET | wss://sns.example.net/streaming?i=[redacted]&_t=[redacted]
Status: 403 Forbidden
Version: HTTP/1.1
Transferred: 599 B (size 0 B)
DNS Resolution: System