I have done a fresh install of kali linux 2020.3 in virtual box. It was just working fine. But after a power off it and start it again /sbin was missing from the $PATH. I tried to add it and was successful until I closed the terminal and opened a new terminal. After opening the new terminal again the problem appeared. Also the while trying to restart network-manager using service command its showing unit network-manager not found.
Code:
$ sudo service network-manager restart
[sudo] password for stryker:
Failed to restart network-manager.service: Unit network-manager.service not found.