Xserver crash always when SteamVR is started

Xserver crash when SteamVR is started

From /var/log/ Xorg.1.log.old

[ 45.171] Build Operating System: linux Ubuntu
[ 45.171] Current Operating System: Linux kathy 5.11.0-44-generic #48~20.04.2-Ubuntu SMP Tue Dec 14 15:36:44 UTC 2021 x86_64
[ 45.171] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-5.11.0-44-generic root=UUID=9c5035b9-3040-42ba-bdda-26879cf67955 ro
[ 45.171] Build Date: 14 December 2021 02:14:13PM
[ 45.171] xorg-server 2:1.20.13-1ubuntu1~20.04.2 (For technical support please see http://www.ubuntu.com/support)
[ 45.189] (II) NVIDIA(0): NVIDIA GPU NVIDIA GeForce RTX 3080 Ti (GA102-A) at PCI:1:0:0
[ 45.189] (--) NVIDIA(GPU-0): HTC Corporation VIVE Pro 2 (DFP-3): connected
[ 45.189] (--) NVIDIA(GPU-0): HTC Corporation VIVE Pro 2 (DFP-3): Internal DisplayPort
[ 45.189] (--) NVIDIA(GPU-0): HTC Corporation VIVE Pro 2 (DFP-3): 2670.0 MHz maximum pixel clock
[ 45.192] (--) NVIDIA(GPU-0): DELL UP3216Q (DFP-6): connected
[ 45.192] (--) NVIDIA(GPU-0): DELL UP3216Q (DFP-6): Internal DisplayPort
[ 45.192] (--) NVIDIA(GPU-0): DELL UP3216Q (DFP-6): 2670.0 MHz maximum pixel clock
[
[ 137.937] (EE)
[ 137.937] (EE) Backtrace:
[ 137.939] (EE) 0: /usr/lib/xorg/Xorg (OsLookupColor+0x13c) [0x55780974caec]
[ 137.939] (EE) 1: /lib/x86_64-linux-gnu/libpthread.so.0 (funlockfile+0x60) [0x7f9486cb43c0]
[ 137.939] (EE) 2: ? (?+0x0) [0x0]

This issue happens always with update published 2022-01-04 ( 2022-01-04 14:28:37 UTC Published Focal security restricted libs 495.46-0ubuntu0.20.04.1)

This did not happen 495 earlier releases. Temporary fix is to downgrade 470 version
Ubuntu 20.04.3 LTS