diff --git a/src/cpp/fastdds/subscriber/DataReaderImpl.cpp b/src/cpp/fastdds/subscriber/DataReaderImpl.cpp
index cfc30b84598..179fc63203b 100644
--- a/src/cpp/fastdds/subscriber/DataReaderImpl.cpp
+++ b/src/cpp/fastdds/subscriber/DataReaderImpl.cpp
@@ -688,11 +688,6 @@ ReturnCode_t DataReaderImpl::read_or_take_next_sample(
         return ReturnCode_t::RETCODE_NOT_ENABLED;
     }
 
-    if (history_.getHistorySize() == 0)
-    {
-        return ReturnCode_t::RETCODE_NO_DATA;
-    }
-
     auto max_blocking_time = std::chrono::steady_clock::now() +
 #if HAVE_STRICT_REALTIME
             std::chrono::microseconds(::TimeConv::Time_t2MicroSecondsInt64(qos_.reliability().max_blocking_time));
@@ -707,6 +702,16 @@ ReturnCode_t DataReaderImpl::read_or_take_next_sample(
         return ReturnCode_t::RETCODE_TIMEOUT;
     }
 
+    auto unread_count = get_unread_count(false);
+    if (history_.getHistorySize() == 0)
+    {
+        auto unread_count_no_history = get_unread_count(false);
+        assert(unread_count_no_history != unread_count || unread_count_no_history == 0);
+        // assert(get_unread_count() == 0);
+        return ReturnCode_t::RETCODE_NO_DATA;
+    }
+
+
     set_read_communication_status(false);
 
     auto it = history_.lookup_available_instance(HANDLE_NIL, false);
diff --git a/src/cpp/rtps/reader/StatefulReader.cpp b/src/cpp/rtps/reader/StatefulReader.cpp
index c1232442e48..7b43ada3eed 100644
--- a/src/cpp/rtps/reader/StatefulReader.cpp
+++ b/src/cpp/rtps/reader/StatefulReader.cpp
@@ -953,6 +953,10 @@ bool StatefulReader::change_removed_by_history(
                 {
                     --total_unread_;
                 }
+                else
+                {
+                    assert(false);
+                }
             }
 
             WriterProxy* proxy = wp;
@@ -1159,6 +1163,7 @@ void StatefulReader::NotifyChanges(
         assert(false == aux_ch->isRead);
         new_data_available = true;
         ++total_unread_;
+        assert(total_unread_ <= mp_history->getHistorySize());
         on_data_notify(proxGUID, aux_ch->sourceTimestamp);
 
         ++it;
@@ -1425,11 +1430,16 @@ void StatefulReader::change_read_by_user(
     // Mark change as read
     if (mark_as_read && !change->isRead)
     {
+        assert(get_last_notified(change->writerGUID) >= change->sequenceNumber);
         change->isRead = true;
         if (0 < total_unread_)
         {
             --total_unread_;
         }
+        else
+        {
+            assert(false);
+        }
     }
 
     if (mark_as_read)