It would be nice to have a proper version that works with Ubuntu 20.04 made by VMware, as now I can not upgrade my workstation because I'll lose connection to all servers that are using this type of VPN.
Is there another compatible VPN client I can use?
I am afraid that the SSL-VPN Client for Ubuntu 20.04 is not supported and this is the last Ubuntu version so I did not understand what you mean by "can not upgrade my workstation"
And no, there is no other VPN Client as it comes embedded in NSX-V. I suggest you to open a SR case with VMware as you are not the first person with this issue and it seems that in the documentation they are not updating the supported versions (seems to me)
By "can not upgrade my workstation" i mean that I'm currently working on Ubuntu 18.04 on my laptop, and this VPN client is very important to me because I must connect to several servers that has this type of VPN on a daily basis, so I can not upgrade to Ubuntu 20.04 if I don't find a solution for this issue.
Oh okay I thought you were already on Ubuntu 20.04, so yes, I recommend you to not update your workstation till confirmation from VMware support.