Remote access only partially working for my setup

I have a problem that is discussed elsewhere too, but I have not found an answer to my problem, so hopefully it is ok to start a new thread. I just set up a Surf SOHO MK3 and it is working well, but I am struggling with a basic VPN connection.

I have two locations and wish to access resources at the site with the Surf. I have set up the Surf to enable Remote user access and I have the machines plugged into it static IP addresses. I have not forwarded any ports or done anything else yet in an effort to limit variables. The remote network has a different IP scheme, but they are both members of a workgroup with the name WORKGROUP.

I tried L2TP but could not connect. PPTP works and I can ping all of the devices on the remote network. I can also access the Surf’s interface using its local IP address and can do the same with my NAS (access its dashboard). What I cannot seem to do is access any content.

I cannot browse to, or map a network drive to any resources on the network though I can do that easily when physically there. I have also tried turning off the software fire walls (Bitdefender and Windows Defender) but this makes no difference. I keep getting the same results that the network device was not found or unreachable. I have also tried connecting with different authentication so I am sure I have the correct access privileges.

It seems like this must be some port that I need to open up or some security measure in Windows I need to disable since the vpn itself seems to be working. I have scoured the forum and general internet, but none of the simple things seem to be my problem. Since my windows install is pretty much basic, I am hopeful this is a common problem that I simply cannot find.