This frequency is also an input to the nationwide law enforcement interop channel LE-5 (aka 1FLAW-39). Output is 168.4625. PL is 167.9
Have you monitored CBP traffic here recently or did this perhaps get reassigned to the new interops frequency set.
This is an FBI repeater output in Phila., PA. That doesn't mean it isn't CBP in your area, though.
Are you certain this is CBP? I've seen this logged as FBI Buffalo Field Office by others.