diff --git a/changelog.d/fixes/9623-connection-test-recovery.md b/changelog.d/fixes/9623-connection-test-recovery.md
new file mode 100644
index 0000000000..413e59ee87
--- /dev/null
+++ b/changelog.d/fixes/9623-connection-test-recovery.md
@@ -0,0 +1 @@
+- fix(resilience): failed connection test now sets a short cooldown so connections recover after transient outages (#9623)
diff --git a/src/app/api/providers/[id]/test/route.ts b/src/app/api/providers/[id]/test/route.ts
index f377b80290..4d440e6936 100644
--- a/src/app/api/providers/[id]/test/route.ts
+++ b/src/app/api/providers/[id]/test/route.ts
@@ -701,6 +701,17 @@ export async function testSingleConnection(connectionId: string, validationModel
       ? makeDiagnosis("ok", "local", null, null)
       : classifyFailure({ error: result.error, statusCode: result.statusCode, provider }));
 
+  // #9623: a failed connection test must not paint the connection permanently red.
+  // Previously a non-terminal failure wrote `testStatus: "error"` with
+  // `rateLimitedUntil: null` — since the cooldown filter only ever skips entries
+  // whose rateLimitedUntil is in the future, a null cooldown left the connection
+  // permanently unavailable after a transient outage. Give non-terminal test
+  // failures a short cooldown so the lazy-recovery path retries them.
+  const terminalTestStatuses = new Set(["banned", "expired", "credits_exhausted"]);
+  const isTerminalFailure =
+    !result.valid && terminalTestStatuses.has(String(diagnosis.code ?? diagnosis.type ?? "").toLowerCase());
+  const testFailureCooldownMs = result.valid ? 0 : 30_000; // 30s retry window
+
   const updateData: Record<string, any> = {
     testStatus: result.valid ? "active" : "error",
     lastError: result.valid ? null : result.error,
@@ -709,7 +720,12 @@ export async function testSingleConnection(connectionId: string, validationModel
     lastErrorType: result.valid ? null : diagnosis.type,
     lastErrorSource: result.valid ? null : diagnosis.source,
     errorCode: result.valid ? null : diagnosis.code || result.statusCode || null,
-    rateLimitedUntil: result.valid ? null : connection.rateLimitedUntil || null,
+    rateLimitedUntil:
+      result.valid || isTerminalFailure
+        ? result.valid
+          ? null
+          : connection.rateLimitedUntil || null
+        : new Date(Date.now() + testFailureCooldownMs).toISOString(),
   };
 
   if (result.valid) {
diff --git a/tests/unit/repro-9623.test.ts b/tests/unit/repro-9623.test.ts
new file mode 100644
index 0000000000..1f6657169e
--- /dev/null
+++ b/tests/unit/repro-9623.test.ts
@@ -0,0 +1,52 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+// #9623: Failed connection test leaves testStatus=error with no recovery path.
+// Previously the route wrote testStatus:"error" + rateLimitedUntil:null, which the
+// lazy-recovery cooldown filter never matches (it only skips FUTURE rateLimitedUntil),
+// leaving the connection permanently unavailable after a transient outage.
+// Fix: non-terminal test failures now get a short future cooldown (30s) so they recover.
+
+test("#9623 fix: non-terminal test failure sets a future rateLimitedUntil", () => {
+  // Simulate the fixed updateData logic
+  const now = Date.now();
+  const terminalTestStatuses = new Set(["banned", "expired", "credits_exhausted"]);
+  const valid = false;
+  const diagnosis = { code: "network_error", type: "upstream" }; // non-terminal
+  const isTerminalFailure = terminalTestStatuses.has(String(diagnosis.code).toLowerCase());
+  const testFailureCooldownMs = 30_000;
+
+  const rateLimitedUntil =
+    valid || isTerminalFailure
+      ? valid
+        ? null
+        : null
+      : new Date(now + testFailureCooldownMs).toISOString();
+
+  assert.ok(
+    rateLimitedUntil !== null,
+    "non-terminal failure should set a future rateLimitedUntil"
+  );
+  const cooldownTime = new Date(rateLimitedUntil as string).getTime();
+  assert.ok(
+    cooldownTime > now,
+    "rateLimitedUntil must be in the future so the lazy-recovery path retries"
+  );
+  assert.ok(
+    cooldownTime <= now + 30_000,
+    "cooldown should be bounded (30s)"
+  );
+});
+
+test("#9623 guard: terminal failures stay terminal (no fake recovery)", () => {
+  const terminalTestStatuses = new Set(["banned", "expired", "credits_exhausted"]);
+  const diagnosis = { code: "banned", type: "terminal" };
+  const isTerminalFailure = terminalTestStatuses.has(String(diagnosis.code).toLowerCase());
+  assert.equal(isTerminalFailure, true, "banned must be terminal");
+});
+
+test("#9623: success resets cooldown to null", () => {
+  const valid = true;
+  const rateLimitedUntil = valid ? null : new Date(Date.now() + 30_000).toISOString();
+  assert.equal(rateLimitedUntil, null, "successful test clears cooldown");
+});