@civodul

Looks like Ubuntu currently has version 1:1snap1-0ubuntu6 derived from the Debian non-esr, unstable-only version [1], and no derived version of the Debian esr version that is meant for ordinary, security-conscious users (old-old-stable, old-stable, stable, stable-sec, testing) [2]. The main Ubuntu derivative is listed in the bottom-right corner of tracker.d.o/package if it exists. So quite different lineages.

[1] tracker.debian.org/pkg/firefox

[2] tracker.debian.org/pkg/firefox