I've labeled a number of our ports as "Cust: somebody", but not all 
appear on the Port --> Customers page.
All the "Cust" labeled ports are on a pair of Junipers and most of them 
work, but a few are skipped (4 out of 11 are skipped).
With debug enabled on the poller, I can see the 'ifalias' containing the 
Cust string:
   ifAlias.519 = Cust: WHRC
I can also see various other OID's for interface ID 519:
   ifDescr.519 = ge-1/0/3
   ifType.519 = ethernetCsmacd
   ifOperStatus.519 = up
   ifName.519 = ge-1/0/3
   etc..
Running version 18.10.9472 (stable)
thanks for your time.
-- 
Clark 159a, MS 46
508/289-3112