Manual CM client install fails over VPN

Hello, we are having an issue where the Configuration Manger client is installing successfully on client computers on the network, but the install/communication is failing on VPN-connected clients outside the office. I have checked the ccmsetup.exe log and there appear to be many error, but I have not been able to determine at which point the setup fails.

Can anyone help to point me in the right direction, anything standing out that I should look into? Thanks in advance.ccmsetup.log