433 MHz reciever range varies with program

Hey yall, first time here so I'm sorry if I break any established decorum. I'm having an issue where depending on where I am in the program, the effective range of my RF remote changes. When it comes to powering on my device and entering into a "Setup Mode" function, the range is about 5 meters. when I enter the function, the range decreases to about 3 inches. its the strangest thing and i cant seem to figure out what the problem is. Has anyone come into contact with this sort of thing? Id link some code but its about 600 lines long and im not sure whats important to the experts on here.

And there is no other device sucking up power such as displays or other devices?
Paul

I have some 5V LED strips that light up when in the function.
It could be a current issue but I tested out the setup on my breadboard and its fine; even when running multiple LED strips.

are you powering the LEDs separately, or through the Arduino?

The power is coming from a 12v battery through a 5v regulator into an Arduino nano which is powering 5v led strip