I've taken the time to check out some LWOTC starter videos, but I've gone in twice now not having any idea how to liberate a region, which seems pretty important to the game.
For most people the infiltration concept is already pretty foreign, so that combined with super unobvious liberation level 2 missions makes it very easy to not even know what the next important mission to the region is, and thus also easy to blow off if don't have a decent amount of infiltration time offered.
To clarify, I had this issue even when I was blasting full haven intel mode and scanning the region with the avenger.

Jumping back a bit, I wasn't too worried about it on my attempts since at the time I had no idea liberation was a thing or later logistical concerns. As a result I'd do all the missions I could with reasonable infiltration, but this never liberated anything so the result was just making a lot of advent angry regions where commonly had to make inactive havens to not be raided.

After deciding something clearly was not working I found guides on how to liberate, but when they say things like "Liberation is challenging for even advanced players, but particularly confusing to beginners of LW2. In part this is because the first mission in the liberation chain is not identified as a liberation mission. You have to just stumble onto it. "
This is a sign of poor game design.
Some simple improved mission labeling text would go a long way in helping this issue.