"make px4_sitl_default" completes no errors, No heartbeats, No FCU Connection

I’ve been using the v.1.8 and have decided recently to update my Firmware, but cannot get mavros to communicate with the FCU. I’m currently using Gazebo to simulate a uav and have been successful in writing a few node for different tasks(in v.1.8), but since i upgraded the firmware, i get no connection to the FCU, nor does QGC see the craft. I’ve been searching everywhere for a solution but cannot find any. Im using the same launch files without any luck, and tried using the built in launch files but, i am still unable to make a connection. I get no heart beats. The vehicle spawns and gazebo loads but the props spin slowly and no messages from the unit are published, all topics message types are unknown, im assuming this is do to the topics never being published. (I’ve noticed when there is a connection the simulated uavs props don’t spin) I’m at a loss and would appreciate any assistance in this matter.
Details: I’ve tried reverted to an older version and its works fine, so im assuming its not my ROS setup? I ran “catkin clean --deinit” then re-cloned from git, then “make posix_sitl_default”, then “catkin_make”, (had to fix a variable name in a the baro driver, “external” --> “is_external_device”) and it compiled with no errors. “roslaunch px4 mavros_posix_sitl.launch” begins a simulation and i can see the nodes but none are publishing, and “rostopic echo -n1 diagnostics” shows no heartbeats and no connection to FCU. Even any tips as to where i might poke around would be awesome, as im losing my mind on this one. Thanks in advance for any potential help.

1-7-19, i was able to get a link with help from this thread Disconnection between Mavros and px4 in gazebo_sitl, still dont know why this is happening but it works for the most part, but i cannot use my all inclusive launch files anymore, need to launch them all separately. I was able to get my custom nodes to launch from the same file by launching mavros_posix_sitl.launch and then my custom node. I need to do more digging because im still not sure why doing it that way works and the other doesnt.

I’m not certain what is happening but when I use the target built by “make posix_sitl_default” in the newer version my model is unresponsive, I was able to get it working again by copying the one I built in a different firmware version. I’m still at a loss as I get no build errors. Again, thanks for any input.