conflicts between static and dhcp ip

We have a static ip network, i’ve added additonal network cards to connect the internet also. I’ve set them to dhcp assign ip’s. I’m not stepping on ip between the 2 ethernet cards. For instance, our server uses 10.10.?.?
and our internet router assigns 192.168.1.?.
But it seems to affect connectivity with internet. If i disable server card then internet works fine. Sometimes they both work together and then sometimes not??