SAML SLO NameQualifier and SPNameQualifier attributes missing

We have external SAML 2 IdP which requires NameQualifier and SPNameQualifier attributes in NameID element set in the SAML LogoutRequest (SLO), like:

   NameQualifier="https://xxx.yyy.com/idp" 
   SPNameQualifier="https://aaa.bbb.com/saml_sp">
   AAdzZWNy...CtBxVYUk=

Now APM (v 11.5.x) seems to send SAML SLO request without those attributes, which causes SLO to fail at the IdP end:

   AAdzZWNy...CtBxVYUk=

Haven't seen any way to add those attributes, or am I missing something? Any ideas?