After an update from build 25729 to Update 2 (build 26981, 27009), tape pools disappear from Tape management. Only default tape pools are available (Free, Imported and Unrecognized).
At the same time, tape pools are still visible on the Backup storage tab.
Issue in the product.
This issue has been fixed in Update 3 (Build 28035). Please update to the latest build.