I'm observing a similar behavior as reported a while ago in this case: https://github.com/kamailio/kamailio/issues/243

It appears that only the last attribute before save() is stored in DB and later restored on lookup()

kamcmd version
kamailio 5.2.5 (x86_64/linux) e10d4f

Script:

$xavp(ulattrs=>PubNetIP) = $si;
$xavp(ulattrs=>PubNetPort) = $sp;
$xavp(ulattrs=>Transport) = $proto;

pv_xavp_print();

save("location", "");

Mysql log:

insert into `location_attrs` (`username`,`ruid`,`last_modified`,`aname`,`atype`,`avalue`,`domain` ) values ('firstuser','uloc-5e855601-2529-1','2020-04-01 23:03:48','Transport',0,'udp','sip.mydomain.net')

MariaDB [(none)]> select * from kamailio.location_attrs;
*************************** 1. row ***************************
           id: 26
         ruid: uloc-5e855601-2529-1
     username: firstuser
       domain: sip.mydomain.net
        aname: Transport
        atype: 0
       avalue: udp
last_modified: 2020-04-01 23:12:48

Kamailio xavp pring in logs: