diff --git a/.github/actions/build/action.yml b/.github/actions/build/action.yml
index 8fa7741c0a..43c4f12aa2 100644
--- a/.github/actions/build/action.yml
+++ b/.github/actions/build/action.yml
@@ -13,6 +13,8 @@ runs:
   using: "composite"
   steps:
     # Pre-configuration steps
+    # (skip ccache for --disable-precompiled-headers because it won't use it)
+    # (skip ccache for optimized because built files are too architecture dependent)
     - if: env.MODE != 'optimized' && ( ! contains(env.EXTRA_OPTIONS, '--disable-precompiled-headers') )
       name: "Restore build cache of this job"
       uses: hendrikmuhs/ccache-action@v1.2
@@ -30,6 +32,28 @@ runs:
     - name: "Build ns-3"
       shell: bash
       run: ./ns3 build
+    - name: "Show ccache stats"
+      shell: bash
+      run: ccache -s
+    # Manage inter-run placeholder for tests
+    - name: "Prepare env and get cache miss rate"
+      shell: bash
+      run: |
+        echo "CACHE_MISS=`./utils/ccache-miss-rate.py`" >> $GITHUB_ENV
+        echo "REF_NAME=`echo $GITHUB_REF_NAME | sed -r 's/[/]+/-/g'`" >> $GITHUB_ENV
+        echo "NOW=$(date +'%Y-%m-%dT%H:%M:%S')" >> $GITHUB_ENV
+        touch build/tests-base.txt
+    - if: env.CACHE_MISS != '0'
+      name: "Create tests placeholder"
+      shell: bash
+      run: |
+        touch build/tests-$BUILD_ID.txt
+    - if: env.CACHE_MISS != '0'
+      name: "Store tests placeholder"
+      uses: actions/cache/save@v4
+      with:
+        key: ${{ format('tests-{0}-{1}-{2}', env.BUILD_ID, env.REF_NAME, env.NOW) }}
+        path: build/tests-*.txt
     # Post-build steps
     - if: inputs.store-artifacts == 'true'
       name: "Tar files to preserve permissions"
diff --git a/.github/actions/test/action.yml b/.github/actions/test/action.yml
index 77395cb4ff..32429a44fa 100644
--- a/.github/actions/test/action.yml
+++ b/.github/actions/test/action.yml
@@ -4,11 +4,31 @@ description: "Defines the central steps in testing ns-3"
 runs:
   using: "composite"
   steps:
-    # Test steps
-    - name: "Store ccache miss rate"
+    - name: "Prepare env"
+      run: |
+        echo "REF_NAME=`echo $GITHUB_REF_NAME | sed -r 's/[/]+/-/g'`" >> $GITHUB_ENV
+        echo "NOW=$(date +'%Y-%m-%dT%H:%M:%S')" >> $GITHUB_ENV
+      shell: bash
+    - name: "Restore tests placeholder"
+      uses: actions/cache/restore@v4
+      with:
+        key: ${{ format('tests-{0}-{1}-', env.BUILD_ID, env.REF_NAME) }}
+        restore-keys: ${{ format('tests-{0}-{1}-', env.BUILD_ID, env.REF_NAME) }}
+        path: build/tests-*.txt
+    - run: ls -al build/ | grep tests
       shell: bash
-      run: echo "CACHE_MISS=`./utils/ccache-miss-rate.py`" >> $GITHUB_ENV
-    - if: env.CACHE_MISS != '0' && env.MODE != 'debug'
-      name: "Test ns-3"
+    # Test steps
+    - name: "Test ns-3"
       shell: bash
-      run: ./test.py -n
+      run: >
+        if [[ "$MODE" != "debug" ]] && [[ -f build/tests-$BUILD_ID.txt ]];
+        then ./test.py -n;
+        if [[ $? == 0 ]];
+        then `rm build/tests-$BUILD_ID.txt` || true;
+        fi;
+        fi
+    - name: "Update tests placeholder"
+      uses: actions/cache/save@v4
+      with:
+        key: ${{ format('tests-{0}-{1}-{2}', env.BUILD_ID, env.REF_NAME, env.NOW) }}
+        path: build/tests-*.txt
diff --git a/test/lorawan-test-suite.cc b/test/lorawan-test-suite.cc
index 6cb77de91c..e8210570ef 100644
--- a/test/lorawan-test-suite.cc
+++ b/test/lorawan-test-suite.cc
@@ -1082,7 +1082,16 @@ class PhyConnectivityTest : public TestCase
     void NoMoreDemodulators(Ptr<const Packet> packet, uint32_t node);
     void WrongFrequency(Ptr<const Packet> packet, uint32_t node);
     void WrongSf(Ptr<const Packet> packet, uint32_t node);
-    bool HaveSamePacketContents(Ptr<Packet> packet1, Ptr<Packet> packet2);
+
+    /**
+     * Compare two packets to check if they are equal.
+     *
+     * \param packet1 A first packet.
+     * \param packet2 A second packet.
+     * \return True if their unique identifiers are equal,
+     * \return false otherwise.
+     */
+    bool IsSamePacket(Ptr<Packet> packet1, Ptr<Packet> packet2);
 
   private:
     void DoRun() override;
@@ -1162,30 +1171,9 @@ PhyConnectivityTest::WrongFrequency(Ptr<const Packet> packet, uint32_t node)
 }
 
 bool
-PhyConnectivityTest::HaveSamePacketContents(Ptr<Packet> packet1, Ptr<Packet> packet2)
+PhyConnectivityTest::IsSamePacket(Ptr<Packet> packet1, Ptr<Packet> packet2)
 {
-    uint32_t size1 = packet1->GetSerializedSize();
-    uint8_t buffer1[size1];
-    packet1->Serialize(buffer1, size1);
-
-    uint32_t size2 = packet2->GetSerializedSize();
-    uint8_t buffer2[size2];
-    packet2->Serialize(buffer2, size2);
-
-    NS_ASSERT(size1 == size2);
-
-    bool foundADifference = false;
-    for (uint32_t i = 0; i < size1; i++)
-    {
-        NS_LOG_DEBUG(unsigned(buffer1[i]) << " " << unsigned(buffer2[i]));
-        if (buffer1[i] != buffer2[i])
-        {
-            foundADifference = true;
-            break;
-        }
-    }
-
-    return !foundADifference;
+    return packet1->GetUid() == packet2->GetUid();
 }
 
 void
@@ -1310,7 +1298,7 @@ PhyConnectivityTest::DoRun()
     LoraTxParameters txParams;
     txParams.sf = 12;
 
-    uint8_t buffer[10] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+    uint8_t buffer[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
     Ptr<Packet> packet = Create<Packet>(buffer, 10);
 
     // Testing
@@ -1496,7 +1484,7 @@ PhyConnectivityTest::DoRun()
     Simulator::Run();
     Simulator::Destroy();
 
-    NS_TEST_EXPECT_MSG_EQ(HaveSamePacketContents(packet, m_latestReceivedPacket),
+    NS_TEST_EXPECT_MSG_EQ(IsSamePacket(packet, m_latestReceivedPacket),
                           true,
                           "Packet changed contents when going through the channel");