diff --git a/convex/tickets.ts b/convex/tickets.ts
index 9f248a4..8b138ab 100644
--- a/convex/tickets.ts
+++ b/convex/tickets.ts
@@ -106,6 +106,53 @@ function normalizeTeams(teams?: string[] | null): string[] {
   return teams.map((team) => renameQueueString(team) ?? team);
 }
 
+type RequesterFallbackContext = {
+  ticketId?: Id<"tickets">;
+  fallbackName?: string | null;
+  fallbackEmail?: string | null;
+};
+
+function buildRequesterSummary(
+  requester: Doc<"users"> | null,
+  requesterId: Id<"users">,
+  context?: RequesterFallbackContext,
+) {
+  if (requester) {
+    return {
+      id: requester._id,
+      name: requester.name,
+      email: requester.email,
+      avatarUrl: requester.avatarUrl,
+      teams: normalizeTeams(requester.teams),
+    };
+  }
+
+  const idString = String(requesterId);
+  const fallbackName =
+    typeof context?.fallbackName === "string" && context.fallbackName.trim().length > 0
+      ? context.fallbackName.trim()
+      : "Solicitante não encontrado";
+  const fallbackEmailCandidate =
+    typeof context?.fallbackEmail === "string" && context.fallbackEmail.includes("@")
+      ? context.fallbackEmail
+      : null;
+  const fallbackEmail = fallbackEmailCandidate ?? `requester-${idString}@example.invalid`;
+
+  if (process.env.NODE_ENV !== "test") {
+    const ticketInfo = context?.ticketId ? ` (ticket ${String(context.ticketId)})` : "";
+    console.warn(
+      `[tickets] requester ${idString} ausente ao hidratar resposta${ticketInfo}; usando placeholders.`,
+    );
+  }
+
+  return {
+    id: requesterId,
+    name: fallbackName,
+    email: fallbackEmail,
+    teams: [],
+  };
+}
+
 type CustomFieldInput = {
   fieldId: Id<"ticketFields">;
   value: unknown;
@@ -348,13 +395,7 @@ export const list = query({
           channel: t.channel,
           queue: queueName,
           company: company ? { id: company._id, name: company.name, isAvulso: company.isAvulso ?? false } : null,
-          requester: requester && {
-            id: requester._id,
-            name: requester.name,
-            email: requester.email,
-            avatarUrl: requester.avatarUrl,
-            teams: normalizeTeams(requester.teams),
-          },
+          requester: buildRequesterSummary(requester, t.requesterId, { ticketId: t._id }),
           assignee: assignee
             ? {
                 id: assignee._id,
@@ -526,13 +567,7 @@ export const getById = query({
       channel: t.channel,
       queue: queueName,
       company: company ? { id: company._id, name: company.name, isAvulso: company.isAvulso ?? false } : null,
-      requester: requester && {
-        id: requester._id,
-        name: requester.name,
-        email: requester.email,
-        avatarUrl: requester.avatarUrl,
-        teams: normalizeTeams(requester.teams),
-      },
+      requester: buildRequesterSummary(requester, t.requesterId, { ticketId: t._id }),
       assignee: assignee
         ? {
             id: assignee._id,
@@ -1434,13 +1469,7 @@ export const playNext = mutation({
       priority: chosen.priority,
       channel: chosen.channel,
       queue: queueName,
-      requester: requester && {
-        id: requester._id,
-        name: requester.name,
-        email: requester.email,
-        avatarUrl: requester.avatarUrl,
-        teams: normalizeTeams(requester.teams),
-      },
+      requester: buildRequesterSummary(requester, chosen.requesterId, { ticketId: chosen._id }),
       assignee: assignee
         ? {
             id: assignee._id,
diff --git a/convex/users.ts b/convex/users.ts
index bc504df..5c96db4 100644
--- a/convex/users.ts
+++ b/convex/users.ts
@@ -2,9 +2,6 @@ import { mutation, query } from "./_generated/server";
 import { ConvexError, v } from "convex/values";
 import { requireAdmin } from "./rbac";
 
-// All roles that have staff-level access in some areas. Do NOT include COLLABORATOR here
-// to avoid leaking collaborators into staff pickers such as "responsável".
-const STAFF_ROLES = new Set(["ADMIN", "MANAGER", "AGENT"]);
 const INTERNAL_STAFF_ROLES = new Set(["ADMIN", "AGENT"]);
 
 export const ensureUser = mutation({
diff --git a/src/components/admin/machines/admin-machines-overview.tsx b/src/components/admin/machines/admin-machines-overview.tsx
index 3f75ac1..7bf3c8d 100644
--- a/src/components/admin/machines/admin-machines-overview.tsx
+++ b/src/components/admin/machines/admin-machines-overview.tsx
@@ -994,16 +994,13 @@ export function MachineDetails({ machine }: MachineDetailsProps) {
   const metrics = machine?.metrics ?? null
   const metricsCapturedAt = useMemo(() => getMetricsTimestamp(metrics), [metrics])
   // Live refresh the relative time label every second when we have a capture timestamp
-  const [relativeTick, setRelativeTick] = useState(0)
+  const [, setRelativeTick] = useState(0)
   useEffect(() => {
     if (!metricsCapturedAt) return
     const id = setInterval(() => setRelativeTick((t) => t + 1), 1000)
     return () => clearInterval(id)
   }, [metricsCapturedAt])
-  const lastUpdateRelative = useMemo(
-    () => (metricsCapturedAt ? formatRelativeTime(metricsCapturedAt) : null),
-    [metricsCapturedAt, relativeTick]
-  )
+  const lastUpdateRelative = metricsCapturedAt ? formatRelativeTime(metricsCapturedAt) : null
   const hardware = metadata?.hardware
   const network = metadata?.network ?? null
   const networkInterfaces = Array.isArray(network) ? network : null
diff --git a/src/components/portal/portal-ticket-detail.tsx b/src/components/portal/portal-ticket-detail.tsx
index 9c0a138..5bbc7c7 100644
--- a/src/components/portal/portal-ticket-detail.tsx
+++ b/src/components/portal/portal-ticket-detail.tsx
@@ -635,7 +635,7 @@ function PortalCommentAttachmentCard({
       window.open(target, "_blank", "noopener,noreferrer")
       toast.error("Não foi possível baixar o anexo automaticamente.", { id: toastId })
     }
-  }, [attachment.name, ensureUrl])
+  }, [attachment.id, attachment.name, ensureUrl])
 
   const resolvedUrl = url
 
diff --git a/src/components/tickets/ticket-comments.rich.tsx b/src/components/tickets/ticket-comments.rich.tsx
index 08b0e61..1415ed1 100644
--- a/src/components/tickets/ticket-comments.rich.tsx
+++ b/src/components/tickets/ticket-comments.rich.tsx
@@ -650,7 +650,7 @@ function CommentAttachmentCard({
       window.open(target, "_blank", "noopener,noreferrer")
       toast.error("Não foi possível baixar o anexo automaticamente.", { id: toastId })
     }
-  }, [attachment.name, ensureUrl, url])
+  }, [attachment.id, attachment.name, ensureUrl, url])
 
   const name = attachment.name ?? ""
   const urlLooksImage = url ? /\.(png|jpe?g|gif|webp|svg)$/i.test(url) : false
diff --git a/src/lib/auth-client.tsx b/src/lib/auth-client.tsx
index 5cc579e..e660bfb 100644
--- a/src/lib/auth-client.tsx
+++ b/src/lib/auth-client.tsx
@@ -109,6 +109,11 @@ export function AuthProvider({ children }: { children: React.ReactNode }) {
   //    carregar o contexto — se a API responder 200, assumimos que há sessão válida
   //    do lado do servidor e populamos o contexto para o restante do app.
   useEffect(() => {
+    if (isPending) {
+      setMachineContextLoading(true)
+      return
+    }
+
     const shouldFetch = Boolean(session?.user?.role === "machine") || !session?.user
     if (!shouldFetch) {
       setMachineContext(null)
@@ -215,7 +220,7 @@ export function AuthProvider({ children }: { children: React.ReactNode }) {
     return () => {
       cancelled = true
     }
-  }, [session?.user])
+  }, [session?.user, isPending])
 
   // Poll machine session periodically to reflect admin changes (e.g., deactivation)
   useEffect(() => {