diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index ffa1d9706..a627947a8 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -38,6 +38,7 @@ Release 3-dev
 - (wifi) #709 Adjust WifiPhy::RxSensitivity with channel width for YansWifiChannel
 - (wifi) Align default TXOP limit for VI and VO to 802.11-2020
 - (wifi) #696 - 802.11ax assert failed. cond="seqNumber < SEQNO_SPACE_SIZE && startingSeqNumber < SEQNO_SPACE_SIZE"
+- (wifi) Fix acknowledgment in SU format for DL MU PPDUs including PSDUs of different TIDs
 
 Release 3.36.1
 --------------
diff --git a/src/wifi/model/block-ack-manager.cc b/src/wifi/model/block-ack-manager.cc
index 21d427196..2709101cd 100644
--- a/src/wifi/model/block-ack-manager.cc
+++ b/src/wifi/model/block-ack-manager.cc
@@ -293,7 +293,8 @@ BlockAckManager::GetBar (bool remove, uint8_t tid, Mac48Address address)
         }
       if (nextBar->bar->GetHeader ().IsBlockAckReq ())
         {
-          AgreementsI it = m_agreements.find (std::make_pair (recipient, nextBar->tid));
+          auto bam = m_bamMap.at (QosUtilsMapTidToAc (nextBar->tid));
+          AgreementsI it = bam->m_agreements.find (std::make_pair (recipient, nextBar->tid));
           if (it == m_agreements.end ())
             {
               // BA agreement was torn down; remove this BAR and continue