diff --git a/setup/register.ts b/setup/register.ts
index dacd8d24b..a15e4698b 100644
--- a/setup/register.ts
+++ b/setup/register.ts
@@ -118,13 +118,6 @@ export async function run(args: string[]): Promise<void> {
     process.exit(4);
   }
 
-  // Chat SDK adapters prefix platform IDs with the channel type (e.g. "telegram:123",
-  // "discord:guild:channel"). Auto-prefix if the user provided a raw ID so the router
-  // matches the adapter's format.
-  if (parsed.platformId && !parsed.platformId.startsWith(`${parsed.channel}:`)) {
-    parsed.platformId = `${parsed.channel}:${parsed.platformId}`;
-  }
-
   log.info('Registering channel', parsed);
 
   // Init v2 central DB
diff --git a/src/router.ts b/src/router.ts
index 658c117ad..89723fc3b 100644
--- a/src/router.ts
+++ b/src/router.ts
@@ -34,7 +34,15 @@ export interface InboundEvent {
  */
 export async function routeInbound(event: InboundEvent): Promise<void> {
   // 1. Resolve messaging group
+  // Adapters send prefixed platform IDs (e.g. "telegram:123") but users may
+  // register with raw IDs ("123"). Try exact match first, then stripped prefix.
   let mg = getMessagingGroupByPlatform(event.channelType, event.platformId);
+  if (!mg) {
+    const prefix = `${event.channelType}:`;
+    if (event.platformId.startsWith(prefix)) {
+      mg = getMessagingGroupByPlatform(event.channelType, event.platformId.slice(prefix.length));
+    }
+  }
 
   if (!mg) {
     // Auto-create messaging group (adapter already decided to forward this)