Cannot change affiliation for some JIDs in MUC

ejabberd version: 26.07

This is a working flow

<iq xmlns="jabber:client" from="miho@movim.eu/Movim.WVMQRA.njmI1AcH-U" to="gnap@conference.movim.eu" type="set" id="FlklGvnYtNRH" xml:lang="en">
    <query xmlns="http://jabber.org/protocol/muc#admin">
        <item affiliation="owner" jid="test@movim.eu"/>
    </query>
</iq>
<iq xml:lang='en' to='miho@movim.eu/Movim.WVMQRA.njmI1AcH-U' from='gnap@conference.movim.eu' type='result' id='FlklGvnYtNRH'/>

<iq xmlns="jabber:client" from="miho@movim.eu/Movim.WVMQRA.njmI1AcH-U" to="gnap@conference.movim.eu" type="get" id="O8O3fZFUb7Oq" xml:lang="en">
    <query xmlns="http://jabber.org/protocol/muc#admin">
        <item affiliation="owner"/>
    </query>
</iq>
<iq xml:lang='en' to='miho@movim.eu/Movim.WVMQRA.njmI1AcH-U' from='gnap@conference.movim.eu' type='result' id='O8O3fZFUb7Oq'>
    <query xmlns='http://jabber.org/protocol/muc#admin'>
        <item jid='edhelas@movim.eu' affiliation='owner'/>
        <item jid='gnap@movim.eu' affiliation='owner'/>
        <item jid='miho@movim.eu' affiliation='owner'/>
        <item jid='test@movim.eu' affiliation='owner'/>
    </query>
</iq>

But for some JIDs it doesn't seems to work.

<iq xmlns="jabber:client" from="miho@movim.eu/Movim.WVMQRA.njmI1AcH-U" to="gnap@conference.movim.eu" type="set" id="5jlNqTFIFmWZ" xml:lang="en">
    <query xmlns="http://jabber.org/protocol/muc#admin">
        <item affiliation="owner" jid="sfu.movim.eu"/>
    </query>
</iq>
<iq xml:lang='en' to='miho@movim.eu/Movim.WVMQRA.njmI1AcH-U' from='gnap@conference.movim.eu' type='result' id='5jlNqTFIFmWZ'/>

<iq xmlns="jabber:client" from="miho@movim.eu/Movim.WVMQRA.njmI1AcH-U" to="gnap@conference.movim.eu" type="get" id="sSX2yF" xml:lang="en">
    <query xmlns="http://jabber.org/protocol/muc#admin">
        <item affiliation="admin"/>
    </query>
</iq>

<iq xml:lang='en' to='miho@movim.eu/Movim.WVMQRA.njmI1AcH-U' from='gnap@conference.movim.eu' type='result' id='sSX2yF'>
    <query xmlns='http://jabber.org/protocol/muc#admin'>
        <item jid='sfu.movim.eu' affiliation='admin'/>
        <item jid='demonstration@movim.eu' affiliation='admin'/>
    </query>
</iq>

The affiliation change doesn't return an error but we see that sfu.movim.eu stays admin there.

The issue only seems to appear for JIDs that are only domains (needed for my SFU service).

Thanks again for all the awesome work !

Start by reproducing the MUC admin XML requests shown in the issue, comparing a normal JID with the domain-only JID sfu.movim.eu. Trace the MUC affiliation handling for domain-only JIDs; done means the set request changes the affiliation and a subsequent query reports the new value.