LrC 16.0 (Windows 11): crashes, freezes, system hangs and broken Remove brush with GPU enabled — all gone with GPU off; regression from 15.6 on two machines (NVIDIA and Intel Arc)

Lightroom Classic Version Number
16.0 [202611041403-7ac14c66], Camera Raw 19.0 [2790] — both machines

OS Version Number
Machine A: Windows 11 Pro 26H2, 10.0.26300
Machine B: Windows 11 Pro 25H2, 10.0.26200
Both with all updates installed. The issue occurs on two different Windows builds.

GPU / Driver
Machine A: NVIDIA GeForce RTX 5080 16 GB, NVIDIA Studio Driver 621.14 (latest)
Machine B: Intel Arc A770 16 GB, driver 32.0.101.8735
The two machines use GPUs from different vendors, each with its own current driver, so the issue is not specific to one vendor or driver.

Camera Model
Panasonic, Canon and Sony raw files — independent of camera brand

Description
Since updating from 15.6 to 16.0, Lightroom Classic is unstable on two machines with completely different hardware:
1. Lightroom Classic closes on its own (crash to desktop).
2. Lightroom Classic freezes and must be terminated from Task Manager.
3. The whole system hangs.
4. The Remove tool (Generative AI enabled) is extremely slow while brushing, and only the first spot pin is displayed; the pins of all subsequent spots are not shown.
With 15.6, the same catalogs and workflow never showed any of these problems.

With Edit > Preferences > Performance > Use Graphics Processor set to Off, ALL of the above disappear and the UI becomes fast and responsive. The regression is therefore in the GPU path of 16.0.

The first trigger observed was reordering photos by drag and drop in a standard collection sorted by Custom Order.

System details
Machine A: AMD Ryzen 9 7900, 64 GB DDR5, NVIDIA RTX 5080, ASUS ProArt X670E-Creator (BIOS 3902). Three displays (1920x1200 + 2x 3840x2160), all connected to the RTX 5080; NVIDIA set as the system-wide GPU. Enable HDR in Library ON. Catalog, previews and cache on NVMe; raw files on internal SATA HDDs.
Machine B: Intel Core i7 (14th gen, 20 logical processors), 32 GB RAM, Intel Arc A770 16 GB. Single 3840x2160 display. Enable HDR in Library OFF.
Both machines run at 150% Windows scaling (144 DPI).
Enable HDR in Library is ON on Machine A and OFF on Machine B, so HDR rendering in the Library is not the cause.

Step-by-step Reproduction Instructions
1. Edit > Preferences > Performance > Use Graphics Processor: Auto.
2. In the Library module, open a standard collection and set Sort to Custom Order.
3. In Grid view, drag photos to new positions repeatedly: after a few moves, Lightroom Classic crashes or freezes.
4. In Develop, press Q, select Remove, enable Use Generative AI and brush over several objects: brushing lags heavily, and only the first spot pin is shown.
5. Set Use Graphics Processor to Off and restart: steps 3 and 4 work normally.

Expected Result
Stable operation with the GPU enabled, as in 15.6.

Actual Result
Crashes, freezes, system hangs and broken Remove brush display with the GPU enabled.

Troubleshooting already done
- MIDI2LR disabled on Machine A: no change. The two machines share no third-party plug-ins except Calibrite Camera Calibration (export-only). Since disabling the GPU removes every symptom, a plug-in cause is unlikely.
- Windows and NVIDIA Studio Driver updated on Machine A after the problems started: no change.
- Use Graphics Processor Off: all problems disappear on both machines.

Crash reports have been submitted for every crash from my Adobe ID, with a description.

Possibly related (macOS, 16.0): https://community.adobe.com/bug-reports-674/lightroom-classic-16-macos-generative-remove-mask-overlay-appears-partially-clipped-1654859

System Info — Machine A (paths and file names removed)
Lightroom Classic version: 16.0 [ 202611041403-7ac14c66 ]
License: Creative Cloud
Language setting: en
Operating system: Windows 11 - Business Edition
Version: 11.0.26300
Application architecture: x64
System architecture: x64
Logical processor count: 24
Processor speed: 3.6GHz
SqLite Version: 3.45.1
Adobe GSDK Version: 1.5.1.431
Built-in memory: 64667.9 MB
Dedicated GPU memory used by Lightroom: 2909.3MB / 15977.0MB (18%)
Real memory available to Lightroom: 64667.9 MB
Real memory used by Lightroom: 6529.0 MB (10.0%)
Virtual memory used by Lightroom: 38701.4 MB
GDI objects count: 1055
USER objects count: 4457
Process handles count: 4374
Memory cache size: 696.5MB
Internal Camera Raw version: 19.0 [ 2790 ]
Maximum thread count used by Camera Raw: 5
Camera Raw SIMD optimization: SSE2,AVX,AVX2
Camera Raw virtual memory: 7760MB / 32333MB (24%)
Camera Raw real memory: 8775MB / 64667MB (13%)
System DPI setting: 144 DPI (high DPI mode)
Desktop composition enabled: Yes
Standard Preview Size: 3862 pixels
Displays: 1) 1920x1200, 2) 3840x2160, 3) 3840x2160
Graphics Processor Info:
DirectX: NVIDIA GeForce RTX 5080 (32.0.16.2114)
Init State: GPU for Export supported by default
User Preference: GPU for Export enabled
Enable HDR in Library: ON
GPU for Preview Generation: Auto (S5_15)
Installed Plugins: AdobeStock, Calibrite Camera Calibration, ColorChecker Camera Calibration, Flickr, Helicon Focus Export, MIDI2LR
Adapters: #1 NVIDIA (10de:2c02, 15977 MB), #2 AMD integrated (1002:164e, no display connected), #3 Microsoft Basic Render
Direct2DEnabled: false
GL_RENDERER: NVIDIA GeForce RTX 5080/PCIe/SSE2
GL_VERSION: 4.6.0 NVIDIA 621.14
GPUDeviceEnabled: false
OGLEnabled: true

System Info — Machine B (paths and file names removed)
Lightroom Classic version: 16.0 [ 202611041403-7ac14c66 ]
License: Creative Cloud
Language setting: it
Operating system: Windows 11 - Business Edition
Version: 11.0.26200
Application architecture: x64
System architecture: x64
Logical processor count: 20
Processor speed: 2.1GHz
SqLite Version: 3.45.1
Adobe GSDK Version: 1.5.1.431
Built-in memory: 32509.4 MB
Internal Camera Raw version: 19.0 [ 2790 ]
Maximum thread count used by Camera Raw: 5
Camera Raw SIMD optimization: SSE2,AVX,AVX2
System DPI setting: 144 DPI (high DPI mode)
Desktop composition enabled: Yes
Standard Preview Size: 3840 pixels
Displays: 1) 3840x2160
Graphics Processor Info:
DirectX: Intel(R) Arc(TM) A770 Graphics (32.0.101.8735)
Init State: GPU for Export supported by default
User Preference: Auto
Enable HDR in Library: OFF
GPU for Preview Generation: Off (S5_15)
Installed Plugins: AdobeStock, Calibrite Camera Calibration, Flickr, HDR Efex Pro 2, Negative Lab Pro v3
Adapters: #1 Intel Arc A770 (8086:56a0, 16258 MB), #2 Microsoft Basic Render
Direct2DEnabled: false
GL_RENDERER: Intel(R) Arc(TM) A770 Graphics
GL_VERSION: 4.6.0 - Build 32.0.101.8735
GPUDeviceEnabled: false
OGLEnabled: true