How to systematically troubleshoot a broken gnu-screen installation?

I recently started to work in a shared Linux cluster that a version of gnu-screen that I consider unacceptably old (4.01, from 2006). I was not able to convince the system's administrators to install a more recent version of gnu-screen, so I installed my own off my home directory, using conda. Unfortunately, even after I installed my long-trusted ~/.screenrc file, my conda-installed instance of gnu-screen does not work well at all. For example, the backspace key does not erase the character to the left of the cursor; instead, it behaves like the space key, at least as far as what shows up on the screen. Hitting the C-r key, which I use *all the time* to search my history, disfigures my screen grotesquely. Other than gnu-screen's "command key" (which I have set to C-h), pretty much any chord involving Ctrl is messed up. Etc. I should emphasize that all these problems emerge only after I start a new gnu-screen session, using my conda-installed instance of gnu-screen. Outside of screen, or when I use the ancient /usr/bin/screen, my terminal behaves normally. Still, I suspect that the problem may have something to do with my TERM variable's setting at the time of invoking screen (namely TERM=xterm-256color), and/or the terminal emulator I am using (iTerm2 running on OS X), but I don't know how to go beyond these hunches. When I search online for solutions to this problem I come across massive amounts of trial-and-error. Is there a systematic, reasonable way to troubleshoot this problem?