Problem with using Mask in LrC

Troubleshooting steps:

1. Most problems with AI masking are caused by older, buggy graphics drivers. Try updating your graphics driver by going directly to the manufacturer's web site:
https://helpx.adobe.com/lightroom-classic/kb/troubleshoot-gpu.html#solution-4

If that doesn't help, please copy/paste here the entire contents of the LR menu command Help > System Info -- that will let us see exactly which versions of hardware and software LR thinks you're running.

2. Try setting Preferences > Performance > Use Graphics Processor to Off. That won't affect AI masking problems, but it might help some of the other symptoms you're experiencing.

3. Try resetting LR's preferences:
https://www.lightroomqueen.com/articles-page/how-do-i-reset-lightrooms-preferences/

LR sometimes soils its preferences file, and resetting it can fix all sorts of wonky behavior. That article explains how to restore the old preferences if resetting doesn't help.

Lightroom Classic version: 12.1 [ 202212072312-d7ab524b ]
License: Creative Cloud
Language setting: en
Operating system: Windows 10 - Home Premium Edition
Version: 10.0.22621
Application architecture: x64
System architecture: x64
Logical processor count: 8
Processor speed: 2.8GHz
SqLite Version: 3.36.0
CPU Utilisation: 3.0%
Built-in memory: 16183.3 MB
Dedicated GPU memory used by Lightroom: 793.8MB / 1928.3MB (41%)
Real memory available to Lightroom: 16183.3 MB
Real memory used by Lightroom: 4173.8 MB (25.7%)
Virtual memory used by Lightroom: 6684.5 MB
GDI objects count: 827
USER objects count: 2412
Process handles count: 2248
Memory cache size: 0.0MB
Internal Camera Raw version: 15.1 [ 1329 ]
Maximum thread count used by Camera Raw: 5
Camera Raw SIMD optimization: SSE2,AVX,AVX2
Camera Raw virtual memory: 1567MB / 8091MB (19%)
Camera Raw real memory: 2360MB / 16183MB (14%)
System DPI setting: 120 DPI
Desktop composition enabled: Yes
Standard Preview Size: 1920 pixels
Displays: 1) 1920x1080
Input types: Multitouch: Yes, Integrated touch: Yes, Integrated pen: No, External touch: No, External pen: No, Keyboard: No

Graphics Processor Info:
DirectX: NVIDIA GeForce MX450 (30.0.15.1236)
Init State: GPU disconnected
User Preference: Auto

Application folder: C:\Program Files\Adobe\Adobe Lightroom Classic
Library Path: D:\CATALOG\CATALOG.lrcat
Settings Folder: C:\Users\arckh\AppData\Roaming\Adobe\Lightroom

Installed Plugins:
1) AdobeStock
2) Flickr
3) Nikon Tether Plugin

Config.lua flags: None

Adapter #1: Vendor : 10de
Device : 1f97
Subsystem : 3f8817aa
Revision : a1
Video Memory : 1928
Adapter #2: Vendor : 8086
Device : 9a49
Subsystem : 3f8817aa
Revision : 1
Video Memory : 80
Adapter #3: Vendor : 1414
Device : 8c
Subsystem : 0
Revision : 0
Video Memory : 0
AudioDeviceIOBlockSize: 1024
AudioDeviceName: $$$/dvaaudiodevice/SystemDefaultAndEffectiveDeviceName=System Default - Speakers (Realtek(R) Audio)#{comment}DVAAU-4201250: Open the audio hardware preferences page.
AudioDeviceNumberOfChannels: 2
AudioDeviceSampleRate: 48000
Build: LR5x19
Direct2DEnabled: false
GL_ACCUM_ALPHA_BITS: 16
GL_ACCUM_BLUE_BITS: 16
GL_ACCUM_GREEN_BITS: 16
GL_ACCUM_RED_BITS: 16
GL_ALPHA_BITS: 0
GL_BLUE_BITS: 8
GL_DEPTH_BITS: 24
GL_GREEN_BITS: 8
GL_MAX_3D_TEXTURE_SIZE: 16384
GL_MAX_TEXTURE_SIZE: 32768
GL_MAX_TEXTURE_UNITS: 4
GL_MAX_VIEWPORT_DIMS: 32768,32768
GL_RED_BITS: 8
GL_RENDERER: NVIDIA GeForce MX450/PCIe/SSE2
GL_SHADING_LANGUAGE_VERSION: 4.60 NVIDIA
GL_STENCIL_BITS: 8
GL_VENDOR: NVIDIA Corporation
GL_VERSION: 4.6.0 NVIDIA 512.36
GPUDeviceEnabled: false
OGLEnabled: true
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