Thanks for this information. I knew there was something wrong with my game.
I did some tests to find out which particular mod destroys my world.
The biggest problem seems to be the WhyEm DLC : Red Dead Offline. Classic Red Dead Offline it work without problems.
I deleted the upscale weapon textures and the enhanced vegetation textures.
After deleting this modification, the world works perfectly (tested for approx. 2h)
Current mods I play with : WhyEm's Particles
Visual_Redemption
VESTIGIA
Terrain Textures Overhaul
Seasons
Remove Screen Effects 1.4
red_dead_offline
LLRO V7.4
crime_law
Complete Horse Overhaul
Best_TAA_and_Visual_Effects
All_Shots_Cause_Bleedouts
+several scripts
I play with a resolution of 4k DLDSR + Quality DLSS, mostly max settings + 225 Peds GameConfig
I hope I helped. I wish you many full trains and animals.