primary-affiliation attribute issues

[TJ Peters]

Hello,

I have been working on integrating with an institution using attribute 
based authorization. They are using the primary-affiliation attribute 
for this. It is coming across to us as this.

<saml2:Attribute Name="primary-affiliation" 
NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:unspecified">
     <saml2:AttributeValue
         xmlns:xs="http://www.w3.org/2001/XMLSchema"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:type="xs:string">softwareaccess
     </saml2:AttributeValue>

In our logs it looks like this attribute is not being processed, despite 
having been defined in the attribute-map.xml. Here are some relevant 
lines of log data from shib.log.

2022-02-11 10:59:57 DEBUG Shibboleth.SSO.SAML2 [298] [client]: 
extracting pushed attributes...
2022-02-11 10:59:57 WARN Shibboleth.AttributeFilter [298] [client]: 
removed value at position (0) of attribute (primary-affiliation) from 
(http://www.okta.com/exk1mrpp879kkb5eC0h8)
2022-02-11 10:59:57 WARN Shibboleth.AttributeFilter [298] [client]: no 
values left, removing attribute (primary-affiliation) from 
(http://www.okta.com/exk1mrpp879kkb5eC0h8)
2022-02-11 10:59:57 DEBUG Shibboleth.SSO.SAML2 [298] [client]: resolving 
attributes...
2022-02-11 10:59:57 DEBUG Shibboleth.SSO.SAML2 [298] [client]: resolving 
attributes...

After doing some research it appears that a similar attribute 
"eduPersonPrimaryAffiliation" is limited to only certain values such as 
"faculty, student, staff, alum, member, affiliate, employee, 
library-walk-in" . Is the attribute "primary-affiliation" treated in the 
same way? If not, can anyone possibly shed some light into why this 
attribute is not being processed by shibboleth?

Thanks,

TJ