When changing the online tape, the online media name, e.g. on the device list, is not updated. Refresh F5 does not resolve the issue. The name is updated only performed when a backup job actually accesses the online tape.
I did not note this behaviour before installing V10.1 Rev 5629, but I wouldn't swear that it wasn't so before. Anyway, the online media label should always be up to date, at least when refeshing the status window.