Admin can neither unlock nor remove a folder

Working as admin I want to remove the FortiClient.app, which is locked. In the Finder this attribute is shown but grayed; therefore I cannot change it. The trouble-maker appears to be the Contents subfolder; Finder shows it a not Locked but attempts to move it to bin fail (hang). Removing the Contents from terminal also fails:

baM1:FortiClient.app marek$ pwd

/Applications/FortiClient.app

baM1:FortiClient.app marek$ ls -la

total 0

drwxr-xr-x@ 3 marek staff 96 Aug 26 2022 ./

drwxrwxr-x 80 root admin 2560 Jul 24 12:41 ../

drwxr-xr-x+ 2 marek staff 64 Jul 24 14:05 Contents/

baM1:FortiClient.app marek$ sudo rm -rf Contents

Password:

rm: Contents: Operation not permitted

Running Fortinet uninstaller does not work: it starts, asks for admin pass, then asks for permission to install helper(!), then promises to uninstall but after Quit nothing happens.

I believe that removing folders/file should be possible (and easy) for admins. Why this does not work for me? Please share a working solution.

I attach several screen-shots illustrating the issue.

Thanks a lot in advance for comments/solution.

Bests,

Marek

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