diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3273c291c83..c6e22d344bf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -67,6 +67,7 @@ Docs: https://docs.openclaw.ai
 - fix(gateway): honor minimal discovery mode for wide-area DNS-SD [AI]. (#80903) Thanks @pgondhi987.
 - slack: enforce reaction notification policy [AI]. (#80907) Thanks @pgondhi987.
 - Enforce gateway command scopes by caller context [AI]. (#80891) Thanks @pgondhi987.
+- Telegram/groups: in single-account setups, treat an explicit empty `accounts.<id>.groups: {}` map the same as undefined so the root `channels.telegram.groups` allowlist still applies, instead of silently dropping every group update under the default `groupPolicy: "allowlist"`. Multi-account semantics are unchanged so per-account explicit-empty groups still scope-disable a single account without affecting siblings; the explicit way to block all groups for any account remains `groupPolicy: "disabled"`. Fixes #79427. Thanks @nikolaykazakovvs-ux.
 - Enforce Slack plugin approval button authorization [AI]. (#80899) Thanks @pgondhi987.
 - Recognize PowerShell -ec inline commands [AI]. (#80893) Thanks @pgondhi987.
 - fix(qqbot): authorize approval button callbacks [AI]. (#80892) Thanks @pgondhi987.
diff --git a/extensions/telegram/src/account-config.ts b/extensions/telegram/src/account-config.ts
index 2652e8c0b91..76fb538c8ad 100644
--- a/extensions/telegram/src/account-config.ts
+++ b/extensions/telegram/src/account-config.ts
@@ -68,9 +68,19 @@ export function mergeTelegramAccountConfig(
   const account = resolveTelegramAccountConfig(cfg, accountId) ?? {};
 
   // Multi-account bots must not inherit channel-level groups unless explicitly set.
+  // Single-account bots fall back to root `channels.telegram.groups` when the
+  // account does not declare its own groups — including the empty-literal case
+  // `accounts.<id>.groups: {}`, which is almost always a config-migration
+  // artifact rather than an intentional "block all" declaration (use
+  // `groupPolicy: "disabled"` for that).
   const configuredAccountIds = Object.keys(cfg.channels?.telegram?.accounts ?? {});
   const isMultiAccount = configuredAccountIds.length > 1;
-  const groups = account.groups ?? (isMultiAccount ? undefined : channelGroups);
+  const hasAccountGroups = account.groups && Object.keys(account.groups).length > 0;
+  const groups = isMultiAccount
+    ? account.groups
+    : hasAccountGroups
+      ? account.groups
+      : channelGroups;
   const allowFrom = resolveMergedAllowFrom({
     baseAllowFrom: base.allowFrom,
     accountAllowFrom: account.allowFrom,
diff --git a/extensions/telegram/src/accounts.test.ts b/extensions/telegram/src/accounts.test.ts
index a0cea0c6408..b0dc49d8eed 100644
--- a/extensions/telegram/src/accounts.test.ts
+++ b/extensions/telegram/src/accounts.test.ts
@@ -536,6 +536,24 @@ describe("resolveTelegramAccount groups inheritance (#30673)", () => {
     expect(resolved.config.groups).toEqual({ "-100123": { requireMention: false } });
   });
 
+  it("inherits channel-level groups when single-account explicitly sets `groups: {}` (regression: #79427)", () => {
+    const resolved = resolveTelegramAccount({
+      cfg: {
+        channels: {
+          telegram: {
+            groups: { "-100123": { requireMention: false } },
+            accounts: {
+              default: { botToken: "123:default", groups: {} },
+            },
+          },
+        },
+      },
+      accountId: "default",
+    });
+
+    expect(resolved.config.groups).toEqual({ "-100123": { requireMention: false } });
+  });
+
   it("does NOT inherit channel-level groups to secondary account in multi-account setup", () => {
     const resolved = resolveTelegramAccount({
       cfg: createMultiAccountGroupsConfig(),
diff --git a/src/config/group-policy.test.ts b/src/config/group-policy.test.ts
index be09a155655..9ab39a87f36 100644
--- a/src/config/group-policy.test.ts
+++ b/src/config/group-policy.test.ts
@@ -169,6 +169,68 @@ describe("resolveChannelGroupPolicy", () => {
       }),
     ).toBe(false);
   });
+
+  it("falls back to root channel groups when account.groups is an empty object (regression: #79427)", () => {
+    const cfg = {
+      channels: {
+        telegram: {
+          groupPolicy: "allowlist",
+          groups: {
+            "-100123": { requireMention: false },
+          },
+          accounts: {
+            default: { botToken: "123:default", groups: {} },
+          },
+        },
+      },
+    } as OpenClawConfig;
+
+    const policy = resolveChannelGroupPolicy({
+      cfg,
+      channel: "telegram",
+      groupId: "-100123",
+      accountId: "default",
+    });
+
+    expect(policy.allowlistEnabled).toBe(true);
+    expect(policy.allowed).toBe(true);
+  });
+
+  it("uses populated account.groups instead of root when both are configured", () => {
+    const cfg = {
+      channels: {
+        telegram: {
+          groupPolicy: "allowlist",
+          groups: {
+            "-100root": { requireMention: false },
+          },
+          accounts: {
+            default: {
+              botToken: "123:default",
+              groups: { "-100account": { requireMention: false } },
+            },
+          },
+        },
+      },
+    } as OpenClawConfig;
+
+    expect(
+      resolveChannelGroupPolicy({
+        cfg,
+        channel: "telegram",
+        groupId: "-100account",
+        accountId: "default",
+      }).allowed,
+    ).toBe(true);
+    expect(
+      resolveChannelGroupPolicy({
+        cfg,
+        channel: "telegram",
+        groupId: "-100root",
+        accountId: "default",
+      }).allowed,
+    ).toBe(false);
+  });
 });
 
 describe("resolveToolsBySender", () => {
diff --git a/src/config/group-policy.ts b/src/config/group-policy.ts
index 9cdd09f26f5..b032f54d36b 100644
--- a/src/config/group-policy.ts
+++ b/src/config/group-policy.ts
@@ -340,6 +340,21 @@ function resolveChannelGroups(
     return undefined;
   }
   const accountGroups = resolveAccountEntry(channelConfig.accounts, normalizedAccountId)?.groups;
+  // In a single-account setup, treat an explicit empty account groups map
+  // (`accounts.<id>.groups: {}`) the same as undefined for fallback: the empty
+  // literal is almost always a config-migration artifact, not an intentional
+  // "block all groups" declaration — the explicit way to block is
+  // `groupPolicy: "disabled"` (or omitting the group from a populated
+  // allowlist). Without this, an empty `{}` paired with the default
+  // `groupPolicy: "allowlist"` silently denies every group update even though
+  // root `channels.<channel>.groups` is populated. Multi-account contexts keep
+  // the existing semantics so per-account explicit-empty groups still scope
+  // disable a single account without affecting siblings.
+  const isMultiAccount = Object.keys(channelConfig.accounts ?? {}).length > 1;
+  if (!isMultiAccount) {
+    const hasAccountGroups = accountGroups && Object.keys(accountGroups).length > 0;
+    return hasAccountGroups ? accountGroups : channelConfig.groups;
+  }
   return accountGroups ?? channelConfig.groups;
 }