Not able to generate/install Lets Encrypt Certificate

I have tried multiple times to install Lets Encrypt Certificate on PBXact100 appliance, it fails no matter what I try. I changed hostname to sperry.ucpbx.net and pinging this name resolves to the correct IP, i can even access the gui but only with https://sperry.ucpbx.net.

I have tried different combinations in Port Management as well - still no resolution. All module and system updates have been installed. 

I have even reinstalled OS with a fresh download (6.24.2019) downloaded directly from Sangoma website. I reactivated with the same deployment ID - and went through all the same motions again, but still no resolve of the issue.

The version installed is not even available under affected versions !!  I am running 14.0.12.1