Massive FPS drops (1–10 FPS) in endgame, 9950x3d / RTX 5080

Hey Exiles,
I’m running into a weird issue where Path of Exile drops from 240+ FPS down to 1–10 FPS whenever there’s a lot of monsters on screen. Elsewhere, everything is buttery smooth.

So far:
*Reinstalled CPU + GPU drivers
*Set CPU/GPU power profiles to maximum performance
*Set Shader Cache to unlimited
*Enabled NVIDIA Smooth Motion
*Unassigned CPU #0 from PoE process
*Set PoE process priority to High
*Linked shader roaming directory → actual game directory (mklink /J)
*Switched RAM from EXPO1 (6000MHz) to EXPO2 (5600MHz) for stability
*Made sure virtual cores 16–31 are parked
*Ran Steam file verification multiple times
*Tried all renderers (DX11, DX12, Vulkan)
*Tried different upscalers (DLSS, XeSS, FSR) and toggled various graphics options
Tried playing on the lowest possible settings


Issue:
*FPS stays around 240 normally
*Drops to 1–10 FPS when huge monster packs appear
*Happens on any renderer or settings combo
*Feels like a CPU/shader stall rather than a GPU bottleneck

System specs:
*GPU: MSI GeForce RTX 5080 Ventus 3X OC Plus — 16 GB GDDR7 (DLSS 4)
*Motherboard: MSI MAG X870 TOMAHAWK WIFI
*CPU: AMD Ryzen 9 9950X3D — 16 cores / 32 threads, AM5 socket, 170 W TDP
*Memory: Patriot Viper Venom DDR5 — 64 GB (2×32 GB) @ 6000 MHz CL30 (PVV564G600C30K)
*Cooling: Arctic Freezer III Pro 360 mm Liquid Cooler
*PSU: Corsair RM1000x (2024 Edition) — 1000 W 80+ Gold
*Storage: Samsung SSD 990 Pro

What else can i try ? Please, i want to play this game a bit more before my vacation ends ;_; .

*Re-installed poe (deleted everything using revo uninstaller)
*Launching game with --nosound flag

still no effect

*Tried older GPU drivers
*tried following these steps - [FIX GUIDE] Solve Shader-Related FPS Drops & Lag Spikes in Path of Exile 2 (PC) https://www.pathofexile.com/forum/view-thread/3800105

*Step include setting cache to 100gb, adding poe.exe to graphics settings
*rn sitting in map with game paused waitting for DRIVE and SHADER to calm down (mby needs to load) ?

*Got a juiced map with 100% deli t16 Full of harbingers in Glacier map, so its really packed with mobs.


*Waited out until drive and shader calms down.
*Unpause - nothing, still getting 10fps

Trying new map, same setup
Drive and Shader loading from scratch ?

Shader green bar full
Drive going 10-50 mb/s

Idk how this works...

*trying to follow Known Issues / FAQ https://www.pathofexile.com/forum/view-thread/1733474

*Set renderer to vulkan and textures to medium, entered map, waitting for drive and shader to calm down.

Issue persists