So if the official instructions don’t enable you to get the UCL VPN service working with the official Cisco client then you should try the following

From testing on various distros, it appears that the Pango Library is required by the client software, not having this generally prevents the software from launching without an obvious error

I’ve tried the following distributions and these all work with the 64bit version of the AnyConnect client version 4.3.02039 or above

• Ubuntu 18.10
• Ubuntu 16.04 LTS
• Linux Mint 18
• Zorin OS 9
• OpenSuse 42.1
• Fedora 25

you can enter the following commands into Terminal to ensure you have the Pango Library installed

Ubuntu 18.10

sudo apt install libgtk2.0-0 libpangox-1.0-0

Ubuntu 16.04

sudo apt install libpangox-1.0-0 

OpenSuse

sudo zypper install libpangox-1_0-0

Fedora

sudo dnf install pangox-compat

Zorin & Mint both worked out of the box and didn’t require any items to get the Cisco AnyConnect client working

Install the library and then follow the guidelines in the UCL Setup guide, that’s all that’s needed - for reference - UCL VPN Guide

I haven’t had time to troubleshoot this on Manjaro, but the following command installs the Pango Library, so thats a good place to start.

sudo pacman -S pangox-compat