Some follow-up with users from the Ubuntu MATE Community forums show that this is occurring on Focal and Groovy; with 5.4, 5.8, and 5.10 kernels.


Following is a list of hardware and graphics information from affected users:

System:
  Host: huppyryzen Kernel: 5.4.0-54-generic x86_64 bits: 64 
  Desktop: MATE 1.24.0 Distro: Ubuntu 20.04.1 LTS (Focal Fossa) 
Machine:
  Type: Desktop Mobo: ASUSTeK model: PRIME B350-PLUS v: Rev X.0x 
  serial: <superuser/root required> UEFI: American Megatrends v: 5602 
  date: 07/14/2020 
Graphics:
  Device-1: AMD Vega 10 XL/XT [Radeon RX Vega 56/64] driver: amdgpu 
  v: kernel 
  Display: x11 server: X.Org 1.20.8 driver: amdgpu,ati 
  unloaded: fbdev,modesetting,vesa resolution: 3440x1440~60Hz 
  OpenGL: 
  renderer: Radeon RX Vega (VEGA10 DRM 3.35.0 5.4.0-54-generic LLVM 11.0.0) 
  v: 4.6 Mesa 20.3.0-rc2

System:
  Host: marptop Kernel: 5.4.0-54-generic x86_64 bits: 64 
  Desktop: MATE 1.24.0 Distro: Ubuntu 20.04.1 LTS (Focal Fossa) 
Machine:
  Type: Laptop System: HP product: HP Laptop 17-ca0xxx v: N/A 
  serial: <superuser/root required> 
  Mobo: HP model: 84D2 v: 91.17 serial: <superuser/root required> UEFI: AMI 
  v: F.21 date: 11/15/2018 
Graphics:
  Device-1: AMD Raven Ridge [Radeon Vega Series / Radeon Vega Mobile Series] 
  driver: amdgpu v: kernel 
  Display: x11 server: X.Org 1.20.8 driver: amdgpu,ati 
  unloaded: fbdev,modesetting,vesa resolution: 1600x900~60Hz 
  OpenGL: renderer: AMD RAVEN (DRM 3.35.0 5.4.0-54-generic LLVM 10.0.0) 
  v: 4.6 Mesa 20.0.8

System:    
    Host: duck-laptop2 Kernel: 5.8.0-29-generic x86_64 bits: 64 Desktop: MATE 1.24.1 
    Distro: Ubuntu 20.10 (Groovy Gorilla) 
Machine:   
    Type: Laptop System: HP product: HP Laptop 15-db0xxx v: Type1ProductConfigId serial: <superuser/root required> 
    Mobo: HP model: 84AE v: 86.20 serial: <superuser/root required> UEFI: Insyde v: F.10 date: 05/31/2018 
Graphics: 
    Device-1: AMD Raven Ridge [Radeon Vega Series / Radeon Vega Mobile Series] driver: amdgpu v: kernel 
    Device-2: Lite-On 1351 type: USB driver: uvcvideo 
    Display: x11 server: X.Org 1.20.9 driver: amdgpu,ati unloaded: fbdev,modesetting,vesa resolution: 1920x1080~60Hz 
    OpenGL: renderer: AMD RAVEN (DRM 3.38.0 5.8.0-29-generic LLVM 11.0.0) v: 4.6 Mesa 20.2.1

System:
    Host: jgjmate-ThinkPad-E595 Kernel: 5.8.0-32-generic x86_64 bits: 64
    Desktop: MATE 1.24.1 Distro: Ubuntu 20.10 (Groovy Gorilla)
Machine:
    Type: Laptop System: LENOVO product: 20NF0012US v: ThinkPad E595
    serial: <superuser/root required>
    Mobo: LENOVO model: 20NF0012US serial: <superuser/root required>
    UEFI: LENOVO v: R11ET39W (1.19 ) date: 09/11/2020
Graphics:
    Device-1: AMD Picasso driver: amdgpu v: kernel
    Device-2: Acer SunplusIT Integrated Camera type: USB driver: uvcvideo
    Display: x11 server: X.Org 1.20.9 driver: amdgpu,ati
    unloaded: fbdev,modesetting,vesa resolution: 1920x1080~60Hz
    OpenGL: renderer: AMD RAVEN (DRM 3.38.0 5.8.0-32-generic LLVM 11.0.0)
    v: 4.6 Mesa 20.2.1

System:
    Host: XXXXXXXX Kernel: 5.4.0-58-generic x86_64 bits: 64
    Desktop: MATE 1.24.0 Distro: Ubuntu 20.04.1 LTS (Focal Fossa)
Machine:
    Type: Laptop System: HP product: HP Laptop 15-db0xxx
    v: Type1ProductConfigId serial: <superuser/root required>
    Mobo: HP model: 84AC v: 85.26 serial: <superuser/root required>
    UEFI: Insyde v: F.22 date: 11/06/2019
Graphics:
    Device-1: AMD Stoney [Radeon R2/R3/R4/R5 Graphics] driver: amdgpu
    v: kernel
    Display: x11 server: X.Org 1.20.8 driver: amdgpu,ati
    unloaded: fbdev,modesetting,vesa resolution: 1366x768~60Hz
    OpenGL: renderer: AMD STONEY (DRM 3.35.0 5.4.0-58-generic LLVM 10.0.0)
    v: 4.5 Mesa 20.0.8

System:    
    Host: pc Kernel: 5.4.0-58-generic x86_64 bits: 64 Desktop: MATE 1.24.0 
    Distro: Ubuntu 20.04.1 LTS (Focal Fossa) 
Machine:   
    Type: Desktop Mobo: MSI model: B75MA-P45 (MS-7798) v: 1.0 serial: <superuser/root required> 
    BIOS: American Megatrends v: 1.9 date: 09/30/2013 
Graphics:  
    Device-1: Advanced Micro Devices [AMD/ATI] Navi 10 [Radeon RX 5600 OEM/5600 XT / 5700/5700 XT] driver: amdgpu 
    v: kernel 
    Display: x11 server: X.Org 1.20.8 driver: amdgpu,ati unloaded: fbdev,modesetting,radeon,vesa 
    resolution: 1366x768~60Hz 
    OpenGL: renderer: AMD Radeon RX 5600 XT (NAVI10 DRM 3.38.0 5.4.0-58-generic LLVM 11.0.0) 
    v: 4.6 Mesa 21.0.0-devel (git-6a34a68 2020-12-13 focal-oibaf-ppa)

System:    
    Host: ACER-xk2308 Kernel: 5.10.4-051004-generic x86_64 bits: 64 Desktop: MATE 1.24.0 
    Distro: Ubuntu 20.04.1 LTS (Focal Fossa) 
Machine:   
    Type: Desktop Mobo: MSI model: B75MA-P45 (MS-7798) v: 1.0 serial: <superuser/root required> 
    BIOS: American Megatrends v: 1.9 date: 09/30/2013 
Graphics:  
    Device-1: Advanced Micro Devices [AMD/ATI] Navi 10 [Radeon RX 5600 OEM/5600 XT / 5700/5700 XT] driver: amdgpu 
    v: kernel 
    Display: x11 server: X.Org 1.20.8 driver: amdgpu,ati unloaded: fbdev,modesetting,radeon,vesa 
    resolution: 1366x768~60Hz 
    OpenGL: renderer: AMD Radeon RX 5600 XT (NAVI10 DRM 3.40.0 5.10.4-051004-generic LLVM 11.0.0) 
    v: 4.6 Mesa 21.0.0-devel (git-24dcdc3 2021-01-04 focal-oibaf-ppa)

System:    
    Host: ACER-xk2308 Kernel: 5.8.0-38-generic x86_64 bits: 64 Desktop: MATE 1.24.0 
    Distro: Ubuntu 20.04.1 LTS (Focal Fossa) 
Machine:   
    Type: Desktop System: MSI product: MS-7798 v: 1.0 serial: <superuser/root required> 
    Mobo: MSI model: B75MA-P45 (MS-7798) v: 1.0 serial: <superuser/root required> BIOS: American Megatrends v: 1.9 
    date: 09/30/2013 
Graphics:  
    Device-1: Advanced Micro Devices [AMD/ATI] Navi 10 [Radeon RX 5600 OEM/5600 XT / 5700/5700 XT] driver: amdgpu 
    v: kernel 
    Display: x11 server: X.Org 1.20.9 driver: amdgpu,ati unloaded: fbdev,modesetting,radeon,vesa 
    resolution: 1366x768~60Hz 
    OpenGL: renderer: AMD Radeon RX 5600 XT (NAVI10 DRM 3.38.0 5.8.0-38-generic LLVM 11.0.1) 
    v: 4.6 Mesa 21.1.0-devel (git-7b48d5d 2021-01-16 focal-oibaf-ppa)

System:
    Host: lorenzo-A315-41 Kernel: 5.4.0-65-generic x86_64 bits: 64
    Desktop: MATE 1.24.0 Distro: Ubuntu 20.04.1 LTS (Focal Fossa)
Machine:
    Type: Laptop System: Acer product: Aspire A315-41 v: V1.18
    serial: <superuser/root required>
    Mobo: RR model: Metapod_RR v: V1.18 serial: <superuser/root required>
    UEFI: Insyde v: 1.18 date: 06/18/2020
Graphics:
    Device-1: AMD Raven Ridge [Radeon Vega Series / Radeon Vega Mobile Series]
    driver: amdgpu v: kernel
    Display: x11 server: X.Org 1.20.9 driver: amdgpu,ati
    unloaded: fbdev,modesetting,vesa resolution: 1366x768~60Hz
    OpenGL: renderer: AMD RAVEN (DRM 3.35.0 5.4.0-65-generic LLVM 11.0.0)
    v: 4.6 Mesa 20.2.6