"- Fixed 0% settlements probability in siege/migration mode after 1.1.0 ."

Does this mean that after 1.1.0 the bitter will not create new bases until it gets fixed?

Only standard settlements occur

Well I quess the positive side is that I can take a bit of brake from factorio now untill it is fixed :)

if there are no more bugs, then the new version will be released faster )

I have a save where migration and siege seem to be broken. (We are using more mods but they shouldn't really effect enemies).

save: https://drive.google.com/file/d/1F3ATHG5BGdmKVpt2RJD3LehGK9x-lyet/view?usp=sharing
mods we are running: https://drive.google.com/file/d/1oHXUJYX7DZWd7ejAg_3TIXZPxHAbbb97/view?usp=sharing

I've run it a little in Singleplayer mode with debugging output enabled, what I noticed is: Temperament is always at 0 and trying to go into negatives, During state AI_STATE_RAIDING only attack squads are created, during AI_STATE_SIEGE no squads are created while "Points" are always capped.

Here's the full debug output:

Rampant Stats:
aN:0, aRN:197, dPB:0, lEU:1219(evoK=0.00625, LEU_evo:7.61875), lEB:87, ARN_AN:1000
temp: 0-->0, points:12985/5081, state:AI_STATE_SIEGE, surface:1 [nauvis]
aS:1, aB:0, atkSize:20.987670490605, stlSize:24.676642890161, formGroup:0.11475108091551, Rtrb = 0

I think maybe the issue is there are no "Active Nests", only "Active Raid Nests"? I have no idea what the difference is.

Yes, the reason is that the siege mode only allows attacks from nearby nests. However, this is not what was meant when version 1.1 was released.
Siege mode fixed
However, something is strange with the migration mode. Testing
27.01.2022 will be 1.1.4

Also noticed that onslaught seemed to not work.

No, aggressive and onslaught modes work as intended - from nearby nests only.
The tests are almost completed, a new version is about to be released.
I must warn you that the AI has accumulated a lot of points. There will be ~30 squads when updating to 1.1.4

Version released. It would be nice to know that everything works not only on my copy, but also on yours

On a quick test it seems to work fine, will report tomorow if it is still fine after extended gamplay with our group.

I saw the stream. Apparently, everything is working fine.
By the way, useful information: during a mass killing, biters form vengence squads even during the day. And they may well choose to target your unprotected outpost