diff --git a/src/activitypub/mocks.js b/src/activitypub/mocks.js
index d3a56866e8..00cf8d1cc3 100644
--- a/src/activitypub/mocks.js
+++ b/src/activitypub/mocks.js
@@ -288,6 +288,7 @@ Mocks.category = async (actors) => {
 			bgColor,
 			backgroundImage,
 			imageClass: 'cover',
+			numRecentReplies: 1,
 			// followerCount,
 			// followingCount,
 
diff --git a/src/categories/recentreplies.js b/src/categories/recentreplies.js
index cb7056bfbb..c162d438b8 100644
--- a/src/categories/recentreplies.js
+++ b/src/categories/recentreplies.js
@@ -10,6 +10,7 @@ const topics = require('../topics');
 const privileges = require('../privileges');
 const plugins = require('../plugins');
 const batch = require('../batch');
+const utils = require('../utils');
 
 module.exports = function (Categories) {
 	Categories.getRecentReplies = async function (cid, uid, start, stop) {
@@ -27,7 +28,7 @@ module.exports = function (Categories) {
 	Categories.updateRecentTid = async function (cid, tid) {
 		const [count, numRecentReplies] = await Promise.all([
 			db.sortedSetCard(`cid:${cid}:recent_tids`),
-			db.getObjectField(`category:${cid}`, 'numRecentReplies'),
+			db.getObjectField(`${utils.isNumber(cid) ? 'category' : 'categoryRemote'}:${cid}`, 'numRecentReplies'),
 		]);
 
 		if (count >= numRecentReplies) {
@@ -131,7 +132,10 @@ module.exports = function (Categories) {
 	function assignTopicsToCategories(categories, topics) {
 		categories.forEach((category) => {
 			if (category) {
-				category.posts = topics.filter(t => t.cid && (t.cid === category.cid || t.parentCids.includes(category.cid)))
+				category.posts = topics.filter(
+					t => t.cid &&
+					(t.cid === category.cid || (t.parentCids && t.parentCids.includes(category.cid)))
+				)
 					.sort((a, b) => b.timestamp - a.timestamp)
 					.slice(0, parseInt(category.numRecentReplies, 10));
 			}
diff --git a/src/controllers/activitypub/topics.js b/src/controllers/activitypub/topics.js
index b2d1c25e7f..b7d6da0095 100644
--- a/src/controllers/activitypub/topics.js
+++ b/src/controllers/activitypub/topics.js
@@ -68,6 +68,12 @@ controller.list = async function (req, res) {
 		categories.getRecentTopicReplies(categoryData, req.uid, req.query),
 		categories.setUnread(data.categories, cids, req.uid),
 	]);
+	data.categories.forEach((category) => {
+		if (category) {
+			helpers.trimChildren(category);
+			helpers.setCategoryTeaser(category);
+		}
+	});
 
 	data.title = translator.escape(data.name);
 	data.privileges = userPrivileges;