Can't get custom DNS to work with VPN

I use Control D for my custom DNS so I can block certain sites & use it while running a VPN. I have that setup on all my devices–1 Android phone, 1 Android tablet, 2 Windows laptops, and my trusty EndeavourOS mini PC. It’s works fine on all of those devices except EndeavourOS. I use ProtonVPN, IVPN, & Wndscribe with my custom DNS and never have a problem with it except on EOS. I’ve tried all 3 VPNs and the VPN connection is good, but it won’t block any of my blocked sites despite using the appropriate resolver IP.

What is it that I’m missing? How can I fix this?