Hello Stortz24 and welcome,
Please login into your DPC3939B (DPC) using a computer with an ethernet cable plugged into any rear LanPorts 1-4, bring up a browser and enter 10.1.10.1, then cus username=cusadmin, password-highspeed. Find the LAN segment connection and if the starting DHCP Server address is 10.1.10.2 then change this to 10.1.10.10, click apply and/or save. This will then provide you 10.1.10.2 through 10.1.10.9 as static addresses you can legitimately force feed into any of your devices due to the legitimate typical default dynamic address table being set to 10.1.10.2 through 10.1.10.252/3.
Please let the forum know if this works for you.