docs: allowing Chrome on Android 17 to reach the local network

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/docs/USERGUIDE.md b/docs/USERGUIDE.md
index ab5ee8ca..7855c234 100644
--- a/docs/USERGUIDE.md
+++ b/docs/USERGUIDE.md
@@ -1103,6 +1103,16 @@ The firewall. A browser on your LAN has to be able to call the node, and a node
 refusing unsolicited inbound UDP cannot be called. See
 [`QUICKSTART.md` Step 9](QUICKSTART.md#step-9--let-people-reach-you).
 
+**On an Android phone, a group opens on mobile data but not on the Wi-Fi its node is on.**
+Android 17 lets an application reach devices on the local network only once
+you allow it, and Chrome comes under that rule from version 155 without asking
+you. Until you allow it, Chrome on the phone cannot reach a node on its own
+Wi-Fi, while on mobile data it reaches the node from outside, so the group
+opens. The group says so rather than
+"DataChannel closed". To allow it: Android **Settings → Apps → Chrome →
+Permissions → Nearby devices → Allow**, then **Retry**. The same goes for any
+other browser you use on the phone. A browser on a computer is not affected.
+
 **A shared directory reads as empty and everything else looks right.**
 A mount the service cannot see. The systemd drop-in needs
 `RequiresMountsFor` as well as `ReadWritePaths` — the service has its own mount