No, it's not an expected behavior.
Core Tunnel persists its configuration in a local SQLite storage file, so we can identify the problem by simply checking the SQLite file.
Please download and install DB Browser for SQLite, then open
~/Library/Containers/io.coressh.tunnel/Data/Library/Application Support/io.coressh.tunnel/CoreSSH.sqlite in the tool, if the sqlite file was restored properly, you should see some records in "ZPROFILE" table like this:
If the table is empty, please restore a fresh copy of the sqlite file from Time Machine, and check the fresh sqlite file by using DB Browser for SQLite.