Cant change the difficulty

[Lord Eistee]

I got the whole anniversary-edition

Mods are the following in order:

Relics of Hyrule SE
SkyUI
Open Cities Skyrim
Spouses Can Live Everywhere
Kaidan 2
Kaidan 2 German
Relationship Dialogue Overhaul - RDO SE
Cathedral Weather and Seasons
Cathedral Landscapes
HD Serpentine Dragon and Mesh Fix SE
Splendor Dragon Variants SE
Splendor Dragon Variants SE (deutsch)
Lucien - Immersive Fully Voiced Male Follower
USSEP German
Diverse Dragon Collections SE
Diverse Dragon Collections SE German translation
Paarthurnax Quest Expansion
Paarthurnax Quest Expansion German
Penitus Oclatus
Penitus Oclatus German
Immersive Armors
Immersive Armor German
Immersive Weapons
Windstad Mine SSE
Windstad Mine SSE German
Killable Children SSE
Stalhrim Source
Miraak - Dragonborn Follower SE
Mortal Enemies SE
Mortal Enemies SE
Rustic Dragon Corpse SE
A Quality World Map
Rudy HQ Nordic Ruins SE
Skyrim Immersive Creatures SE
Visual Animated Enchants 2
Run For Your Lives
Run For Your Lives German
Undergrund - a dungeon texture overhaul
Deadly Spell Impacts
Bellyaches Animal and Creature Pack
Believable weapons
Project New Reign - Nemesis Unlimited Behaviour Engine
Adress Library for SKSE Plugins
Display Enemy Level

DISABLED MODS:

FNIS
RaceMenu
XP32 MSSE
JContainers SE
Ecotone Dual Sheath

Any Ideas what could be the issue?

[Lord Eistee]

It seems to be SkyUI. But why SkyUI...