Not able to call meshed apps from different ns

i have 2 ns, both meshed with linkerd
ns1, centos pod
ns2, booksapp
when control plane is up, works like charm, i can curl http://books.booksapp:7002/books -vv
when control is down, can not call booksapp from my centos pod.
any idea?

yes, for booksapp ns, i refreshed web page, no issues, seems different ns has issue when control is down ?any practice