Chomper prevents me from accessing *any* webpage

[LZua]

• Do you want to request a feature or report a bug?
  I am reporting what I think is a severe bug.

• What is the current behavior?
  Regardless of what configurations I try in my black-list or white-list blocks, as soon as I execute chomper to activate a block, I can't access any website. More specifically, when trying to access the blocked ones, I receive the chomper message as expected.
  However, whenever I try to access any other sites, the web-browser (I tried Firefox, Chrome and Chromium) says that navigating to the requested page is not safe and does not allow me to continue (not even allowing me to say that I want to proceed under my own risk). It is reported also that the software preventing the access is "mitmproxy".
  This is, activating chomper effectively prevents me from navigating to any site.

• If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem via
  There is no possible reproducible example because this happens with any chomper configuration.

• What is the expected behavior?
  Clearly, what should be expected is that the web-pages not black-listed should open.

• Please tell us about your environment:

  • Chomper Release or Commit: the most current as of 10-16-2019
  • Browser: e.g. Firefox 69.0.2, Chromium 77.0.3865.90
  • Operating System: e.g. Linux Ubuntu 18.04 (64bits)