Control panel shows the cached memory as used as well. Your free -m shows the actual result.
To get a better understanding of Linux memory usage, please refer to http://www.linuxatemyram.com/
When receiving the following message:"error creating external connectivity network: cannot...
You may receive the following error message while trying to enable ufw (ufw enable):ERROR:...
If you cannot start OpenVPN on your VPS with Ubuntu 18.04, Debian 9 or CentOS 7 with the...
It probably isn't. You may be reading it incorrectly. Please refer to http://www.linuxatemyram.com/
You do not need to clear your RAM cache. Linux has many decades of excellent memory management...