diff --git a/server/src/routes/issues.ts b/server/src/routes/issues.ts
index bc938910..0213ded2 100644
--- a/server/src/routes/issues.ts
+++ b/server/src/routes/issues.ts
@@ -28,6 +28,8 @@ import { assertCompanyAccess, getActorInfo } from "./authz.js";
 import { shouldWakeAssigneeOnCheckout } from "./issues-checkout-wakeup.js";
 import { isAllowedContentType, MAX_ATTACHMENT_BYTES } from "../attachment-types.js";
 
+const MAX_ISSUE_COMMENT_LIMIT = 500;
+
 export function issueRoutes(db: Db, storage: StorageService) {
   const router = Router();
   const svc = issueService(db);
@@ -878,7 +880,10 @@ export function issueRoutes(db: Db, storage: StorageService) {
       typeof req.query.limit === "string" && req.query.limit.trim().length > 0
         ? Number(req.query.limit)
         : null;
-    const limit = limitRaw && Number.isFinite(limitRaw) && limitRaw > 0 ? Math.floor(limitRaw) : null;
+    const limit =
+      limitRaw && Number.isFinite(limitRaw) && limitRaw > 0
+        ? Math.min(Math.floor(limitRaw), MAX_ISSUE_COMMENT_LIMIT)
+        : null;
     const comments = await svc.listComments(id, {
       afterCommentId,
       order,
diff --git a/server/src/services/heartbeat.ts b/server/src/services/heartbeat.ts
index 1a9dba74..eec83d08 100644
--- a/server/src/services/heartbeat.ts
+++ b/server/src/services/heartbeat.ts
@@ -623,6 +623,19 @@ export function heartbeatService(db: Db) {
       .then((rows) => rows[0] ?? null);
   }
 
+  async function getOldestRunForSession(agentId: string, sessionId: string) {
+    return db
+      .select({
+        id: heartbeatRuns.id,
+        createdAt: heartbeatRuns.createdAt,
+      })
+      .from(heartbeatRuns)
+      .where(and(eq(heartbeatRuns.agentId, agentId), eq(heartbeatRuns.sessionIdAfter, sessionId)))
+      .orderBy(asc(heartbeatRuns.createdAt), asc(heartbeatRuns.id))
+      .limit(1)
+      .then((rows) => rows[0] ?? null);
+  }
+
   async function resolveNormalizedUsageForSession(input: {
     agentId: string;
     runId: string;
@@ -672,6 +685,7 @@ export function heartbeatService(db: Db) {
       };
     }
 
+    const fetchLimit = Math.max(policy.maxSessionRuns > 0 ? policy.maxSessionRuns + 1 : 0, 4);
     const runs = await db
       .select({
         id: heartbeatRuns.id,
@@ -683,7 +697,7 @@ export function heartbeatService(db: Db) {
       .from(heartbeatRuns)
       .where(and(eq(heartbeatRuns.agentId, agent.id), eq(heartbeatRuns.sessionIdAfter, sessionId)))
       .orderBy(desc(heartbeatRuns.createdAt))
-      .limit(Math.max(policy.maxSessionRuns + 1, 4));
+      .limit(fetchLimit);
 
     if (runs.length === 0) {
       return {
@@ -695,7 +709,10 @@ export function heartbeatService(db: Db) {
     }
 
     const latestRun = runs[0] ?? null;
-    const oldestRun = runs[runs.length - 1] ?? latestRun;
+    const oldestRun =
+      policy.maxSessionAgeHours > 0
+        ? await getOldestRunForSession(agent.id, sessionId)
+        : runs[runs.length - 1] ?? latestRun;
     const latestRawUsage = readRawUsageTotals(latestRun?.usageJson);
     const sessionAgeHours =
       latestRun && oldestRun
diff --git a/server/src/services/issues.ts b/server/src/services/issues.ts
index d6f5a643..c42ac02a 100644
--- a/server/src/services/issues.ts
+++ b/server/src/services/issues.ts
@@ -27,6 +27,7 @@ import { resolveIssueGoalId, resolveNextIssueGoalId } from "./issue-goal-fallbac
 import { getDefaultCompanyGoal } from "./goals.js";
 
 const ALL_ISSUE_STATUSES = ["backlog", "todo", "in_progress", "in_review", "blocked", "done", "cancelled"];
+const MAX_ISSUE_COMMENT_PAGE_LIMIT = 500;
 
 function assertTransition(from: string, to: string) {
   if (from === to) return;
@@ -1070,7 +1071,10 @@ export function issueService(db: Db) {
     ) => {
       const order = opts?.order === "asc" ? "asc" : "desc";
       const afterCommentId = opts?.afterCommentId?.trim() || null;
-      const limit = opts?.limit && opts.limit > 0 ? Math.floor(opts.limit) : null;
+      const limit =
+        opts?.limit && opts.limit > 0
+          ? Math.min(Math.floor(opts.limit), MAX_ISSUE_COMMENT_PAGE_LIMIT)
+          : null;
 
       const conditions = [eq(issueComments.issueId, issueId)];
       if (afterCommentId) {
@@ -1085,7 +1089,15 @@ export function issueService(db: Db) {
 
         if (!anchor) return [];
         conditions.push(
-          sql<boolean>`(${issueComments.createdAt} > ${anchor.createdAt} OR (${issueComments.createdAt} = ${anchor.createdAt} AND ${issueComments.id} <> ${anchor.id}))`,
+          order === "asc"
+            ? sql<boolean>`(
+                ${issueComments.createdAt} > ${anchor.createdAt}
+                OR (${issueComments.createdAt} = ${anchor.createdAt} AND ${issueComments.id} > ${anchor.id})
+              )`
+            : sql<boolean>`(
+                ${issueComments.createdAt} < ${anchor.createdAt}
+                OR (${issueComments.createdAt} = ${anchor.createdAt} AND ${issueComments.id} < ${anchor.id})
+              )`,
         );
       }
 
@@ -1093,7 +1105,10 @@ export function issueService(db: Db) {
         .select()
         .from(issueComments)
         .where(and(...conditions))
-        .orderBy(order === "asc" ? asc(issueComments.createdAt) : desc(issueComments.createdAt));
+        .orderBy(
+          order === "asc" ? asc(issueComments.createdAt) : desc(issueComments.createdAt),
+          order === "asc" ? asc(issueComments.id) : desc(issueComments.id),
+        );
 
       const comments = limit ? await query.limit(limit) : await query;
       return comments.map(redactIssueComment);