We are experiencing an issue with users not being mapped to their corresponding network drives during the login. I verified that the logon script is correct and it work if I run it manually so I suspect there is some kind of network issue. When I run gupdate I get an error that states that Group Policy failed because of lack network connectivity to the domain controller. I can ping our dc server immediately after I get the error. I figured this was somehow related to the DNS and/or DHCP server. The DNS server is running on DC and DHCP is running on Pfsense. Should I move the DHCP server to the DC?
There's no reason to. In fact, it's best security practice not to run it on a DC. The only reason I ever set up a DHCP server on a DC is in SMB networks that don't have any other choice.
DHCP and DNS on the same server should not have have any issues. If it's possible try to put static ip on a host and try the whole process again. If no problem occurs you MIGHT have a problem with the DHCP server.
You can also also unplug the lan connection and replug it after a while to check how long it takes DHCP to provide an IP.
From my experience if it's no problem (for SMB) or management issue static ip is the way to go.
Hope it helps.