I tried the procedure to activate continuous updates on Netrunner Debian 19.01, but I have not done updates because I found something, lets say, curious on the list of upgradable packages. If, as the original guide says, I activate both the Debian Testing repo and the netrunner-backports repo, it actually wants to downgrade Firefox from ver. 64 to ver 52 (I guess that is the ESR version)…if I only activate the Debian Testing repo without the netrunner-backports, there is no change on Firefox…so far looking at the upgradable packages list, Firefox is the only one that would be downgraded, and only when using the netrunner-backports repo…is there a way to correct this?
For now I would suggest you simply remove the component plasmazilla from the netrunner-backport.list file. Just removing this keyword from the file in /etc/apt/sources.list.d/ should be enough and Firefox downgrade should not appear anymore after sudo apt update && sudo apt upgrade