Get Skullmining those Advent Officers in mission with 'Find a Lead' in them. Then research the 'Facility Lead'. Gotta keep taking down those pesky Avatar project sites. The speed suggests it was building up all the time in the background..Dark Events etc. You been going on 'revealed' avatar 'project meter bonus' missions to slow them down or missed quite a few?

I've been doing regular "story" missions and the occassional facility mission to keep down the avatar bar. Its worked up until this point, but even so the average has been around 3-4 avatar progress a month. Which is quite a lot, even with a 20 tile progress bar. Granted though, I know there were -a lot- of facilities I didnt hit. I couldnt imagine though that they'd all progress in such bursts.

Admittedly, I had no idea "find a lead" missions actually yielded facility leads through skullmining. Definetly gotta give that a go in my next playthrough.
Also, what are these "revealed avatar project meter bonus missions"? I dont think I've seen missions with that anywhere in the description.

Same thing happened to me. Made me stop playing.

copied this from another thread:

With 3 pips on the Avatar Project still blank I started infiltrating the first (story) blacksite, which takes forever.(almost a month?).
I was this late, because BOTH! blacksite story missions were in the same region with an INITIAL advent sterngth of 9 after making contact. Bringing it down to 6 took forever.
in restrospect obviously I was too late, but how should I know, In vanilla this was ample time to spare. so if you read this, 3 pips blank is when you start to panic, and probably allready lost.

While InfiItrating, the last three pips on the avatar project fill up. No problem I think. I play the mission on 200% infiltratrion, on advent str. 6, with 6 days on the "Alarm" counter left, thinking I did well to wait, because the opposition was still brutal, and most of the 38 clustered closely together.

While still infiltrating the black site (because of "Avatar Alarm mode"), I even get a second Team together for attacking an avatar facility. Infiltration with 10 men takes even longer, but attacking the blacksite removes three pips, right, ao I felt kinda safe. So in effekt, Infiltrating was allready underway with three pips on avatar to go.

Then in just 5 days, the pips fill up again and the timer starts counting down from where it stopped previously (at only 6 days to go) and infiltration still only at 20%. So from 3 pips down on the Avatar Project, to "You lost, Game Over" in under two weeks!

So from thinking I finally get to stop the Avatar project, I loose the game in just 2 weeks, because it decides I should. Avatar progressed 6 Pips in under a month! This really annoys me no end. Yeah, I guess its something to learn again in my ongoing quest on understanding how to beat the game, but this was after 88 Missions.

I wish someone would just make a mod to remove it already. Hate the avatar Project.

I think there is a mod that removes it. I will be looking for it, the next time I play. Tired of loosing to bullsh!t randomness. Two campaigns back to back, lost t the doom meter - not one facility lead in both playthoughs. My doom meter is full, I complete my mission with an intel package, and what do I get, some intel, or some supply, or some ammo, or the best of them all, some rookies - cause rookies are great to use in the end game, they really give them Mutton Elites a fight to remember. 4 empty pips, all fill fill up, I run 4 missions with intel packages, and no facility leads both times. Yeah, done with that sh!t!