Watchdog and Monitor looked the partner up by exact key, and the remote probe passed a quote to cut as a filename

Plugin/unraid/include/monitor.php

@@ -1,5 +1,6 @@
 <?php
 require_once __DIR__ . '/common.php';
+require_once __DIR__ . '/partnership.php';   // vv_pt_peer_match() — tailnet name vs conf hostname
 
 // ═══════════════════════════════════════════════════════════════════════════════════════════════
 // PURPOSE
@@ -94,7 +95,11 @@ function vv_partner_state(): array {
         if (!$hostname) continue;
         $isMe    = ($id === $myHostId);
         $isOwner = strcasecmp($id, $vars['PARTNERSHIP_OWNER_HOST'] ?? '') === 0;
-        $online  = $isMe ? true : ($tsPeers[strtolower($hostname)] ?? null);
+        // Exact-key lookup, until now. The tailnet name and the conf hostname differ by one
+        // character on this mesh, so the partner card reported a host that was up as unknown.
+        // Same unambiguous-prefix rule as everywhere else — one candidate or none.
+        $peerKey = $isMe ? null : vv_pt_peer_match(array_keys($tsPeers), $hostname);
+        $online  = $isMe ? true : ($peerKey !== null ? $tsPeers[$peerKey] : null);
         $onboardPhase = $isMe ? null
             : (($setupDb[$id . '_PHASE2_DONE'] ?? '') === 'true' ? 2
               : (($setupDb[$id . '_PHASE1_DONE'] ?? '') === 'true' ? 1 : 0));